01424nas a2200229 4500008004100000022001400041245008600055210006900141260007700210300001200287490000700299520055300306653002400859653003000883653003800913653002500951100002600976700002001002700002501022700002801047856011901075 2014 eng d a0934-086600aSynthesis and reactivity of magnetically diverse Au@ Ni core-shell nanostructures0 aSynthesis and reactivity of magnetically diverse Au Ni coreshell aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcFEB a236-2440 v313 a

Core-shell bimetallic Au@Ni nanoparticles, with gold cores and thin nickel shells with overall size less than 10 nm, are synthesized and stabilized in pure cubic (fcc) and hexagonal (hcp) phase. Due to their unique crystal, electronic, and geometric structure, they show interesting magnetic and chemical properties. The Au@Ni-fcc is magnetic, whereas Au@Ni-hcp is non-magnetic. Both the bimetallic nanostructures are stable to surface oxidation until 150 degrees C and show excellent catalytic activity for p-nitrophenol reduction reaction.

10aAu-Ni nanoparticles10abimetallic nanostructures10amagnetic core-shell nanoparticles10aoxidation resistance1 aBharathan, Vysakh, A.1 aRaj, Govind, K.1 aJoy, Pattayil, Alias1 aVinod, Chathakudath, P. uhttps://library.ncl.res.in/content/synthesis-and-reactivity-magnetically-diverse-au-ni-core-shell-nanostructures-001644nas a2200229 4500008004100000022001400041245012700055210006900182260007700251300001400328490000600342520075500348653002601103653002301129653001401152653001201166100003501178700002801213700001701241700002801258856012801286 2015 eng d a1867-388000aActivity enhancement upon the incorporation of titanium: au@ti-sio2 core-shell nanocatalysts for the CO oxidation reaction0 aActivity enhancement upon the incorporation of titanium autisio2 aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcAPR a1222-12300 v73 a

The encapsulation of gold nanoparticles 8-12nm in size within a porous Ti-SiO2 shell to form a core-shell nanoarchitecture was investigated, and the catalytic activity of the resulting structure was probed. Detailed characterization of the synthesized materials shows that the core-shell morphology is lost beyond a certain amount of incorporated titanium, and results in normal gold-supported Ti-SiO2. The material has a high surface area (913m(2)g(-1)) and high porosity, both of which make it an excellent choice for catalytic applications. With the optimum amount of incorporated Ti, the core-shell catalyst shows excellent room-temperature CO oxidation activity over several cycles with retention of its morphology at higher temperatures.

10acore-shell structures10agold nanoparticles10aOxidation10aTi-SiO21 aSekhar, Anandakumari, C. Sunil1 aZiyad, Kottavarithottil1 aSoni, Yogita1 aVinod, Chathakudath, P. uhttps://library.ncl.res.in/content/activity-enhancement-upon-incorporation-titanium-auti-sio2-core-shell-nanocatalysts-co-001806nas a2200205 4500008004100000022001400041245010400055210006900159260000900228300001000237490000600247520107000253100002101323700002201344700002001366700002501386700002801411700003001439856013101469 2015 eng d a2045-232200aPd loaded amphiphilic COF as catalyst for multi-fold Heck reactions, C-C couplings and CO oxidation0 aPd loaded amphiphilic COF as catalyst for multifold Heck reactio cJUN  a108760 v53 a

COFs represent a class of polymers with designable crystalline structures capable of interacting with active metal nanoparticles to form excellent heterogeneous catalysts. Many valuable ligands/monomers employed in making coordination/organic polymers are prepared via Heck and C-C couplings. Here, we report an amphiphilic triazine COF and the facile single-step loading of Pd-0 nanoparticles into it. An 18-20% nano-Pd loading gives highly active composite working in open air at low concentrations (Conc. Pd(0) < 0.05 mol%, average TON 1500) catalyzing simultaneous multiple site Heck couplings and C-C couplings using `non-boronic acid' substrates, and exhibits good recyclability with no sign of catalyst leaching. As an oxidation catalyst, it shows 100% conversion of CO to CO2 at 150 degrees C with no loss of activity with time and between cycles. Both vapor sorptions and contact angle measurements confirm the amphiphilic character of the COF. DFT-TB studies showed the presence of Pd-triazine and Pd-Schiff bond interactions as being favorable.

1 aMullangi, Dinesh1 aNandi, Shyamapada1 aShalini, Sorout1 aSreedhala, Sheshadri1 aVinod, Chathakudath, P.1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/pd-loaded-amphiphilic-cof-catalyst-multi-fold-heck-reactions-c-c-couplings-and-co-oxidation02076nas a2200289 4500008004100000022001400041245008500055210006900140260000900209300001200218490000800230520120100238653001801439653001701457653001101474653000901485653001101494100001801505700001601523700002201539700002601561700001701587700001701604700002801621700002401649856011301673 2016 eng d a1387-181100aHighly stable In-SBA-15 catalyst for vapor phase Beckmann rearrangement reaction0 aHighly stable InSBA15 catalyst for vapor phase Beckmann rearrang cNOV  a293-3020 v2343 a

The Indium doped SBA-15 material was prepared by sol-gel method and tested for vapor phase Beckman rearrangement reaction. Among three indium loading, In/Si ratio of 2/100 was found as an optimum composition in terms of caprolactam selectivity (100%) and cyclohexanone oxime conversion (100%). The catalysts were characterized by N-2 adsorption, small-angle X-rays/neutron scattering (SAXS/SANS), XRD, FESEM, HRTEM, EDX, UV, FTIR and NH3-TPD techniques. In-situ SANS experiment was performed on the adsorption of CO2 to detect the micropores in the mesopore wall. All catalysts samples have highly ordered hexagonal structure with well dispersed indium in the silica matrix. The fine tuning of weak and strong acid sites were found in indium doped SBA-15 (In/Si = 2/100) catalyst. The same catalyst showed optimum catalytic performance, high space time yield 114.4 mol/h/g(cat) and high stability till 6 h of reaction without deactivation. The micro-kinetic analysis showed that there were no external and internal diffusion limitations in the SBA-15 catalyst. The reaction mechanism of Beckmann rearrangement over In-SBA-15 has been elucidated. (C) 2016 Elsevier Inc. All rights reserved.

10ae-Caprolactam10aIn-situ SANS10aindium10aSAXS10aSBA-151 aKumar, Rawesh1 aShah, Sneha1 aBahadur, Jitendra1 aMelnichenko, Yuri, B.1 aSen, Debasis1 aMazumder, S.1 aVinod, Chathakudath, P.1 aChowdhury, Biswajit uhttps://library.ncl.res.in/content/highly-stable-sba-15-catalyst-vapor-phase-beckmann-rearrangement-reaction02113nas a2200229 4500008004100000022001400041245008000055210006900135260000900204300002300213490000600236520133300242100002201575700002601597700002101623700002701644700001801671700002801689700002401717700003001741856011201771 2016 eng d a1614-683200aLow band gap benzimidazole COF supported Ni3N as highly active OER catalyst0 aLow band gap benzimidazole COF supported Ni3N as highly active O cDEC  aArticle No:16011890 v63 a

Covalent organic frameworks (COFs) have structures and morphologies closely resembling graphenes, whose modular construction permits atomiclevel manipulations. This, combined with their porous structure, makes them excellent catalyst supports. Here, the high electrocatalytic activity of a composite, formed by supporting Ni3N nanoparticles on a benzimidazole COF, for oxygen evolution reaction is shown. The composite oxidizes alkaline water with a near-record low overpotential of 230 mV @ 10 mA cm(-2) (eta(10)). This high activity is attributed to the ability of the COF to confine the Ni3N nanoparticles to size regimes otherwise difficult to obtain and to its low band gap character (1.49 eV) arising from the synergy between the conducting Ni3N nanoparticles and the pi-conjugated COF. The COF itself, as a metalfree self-standing framework, has an oxygen evolution reaction activity with 10 of 400 mV. The periodic structure of the COF makes it serve as a matrix to disperse the catalytically active Ni3N nanoparticles favoring their high accessibility and thereby good charge-transport within the composite. This is evident from the amount of O-2 evolved (230 mmol h(-1) g(-1)), which, to the best of our knowledge, is the highest reported. The work reveals the emergence of COF as supports for electrocatalysts.

1 aNandi, Shyamapada1 aSingh, Santosh, Kumar1 aMullangi, Dinesh1 aIllathvalappil, Rajith1 aGeorge, Leena1 aVinod, Chathakudath, P.1 aKurungot, Sreekumar1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/low-band-gap-benzimidazole-cof-supported-ni3n-highly-active-oer-catalyst01831nas a2200169 4500008004100000022001400041245014100055210006900196260011000265300001400375490000700389520106800396100001701464700002801481700002201509856013001531 2016 eng d a1144-054600aSimple, phosphine free, reusable Pd(II)-2,2 `-dihydroxybenzophenone-SBA-15 catalyst for arylation and hydrogenation reactions of alkenes0 aSimple phosphine free reusable PdII22 dihydroxybenzophenoneSBA15 aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJAN a2423-24320 v403 a

An efficient, simple, phosphine and co-catalyst free C-C coupling reaction heterogeneous catalyst via a post grafting method is developed and reported. A covalently anchored phosphine free Pd(II) based 2,2'-dihydroxybenzophenone (DHBP) complex over organofunctionalized SBA-15 has been synthesized by the reaction between aminofunctionalized SBA-15 (NH(2)SBA-15) and a 2,2'-dihydroxybenzophenone (DHBP) ligand, and further complexation with Pd(II)Cl-2 to get Pd(II)-DHBP@ SBA-15. The synthesized catalysts were characterized by elemental analysis, XRD, N-2 sorption analyses, TG, DTA, FT-IR, solid state C-13 and Si-29 NMR spectra, XPS, UV-Visible, SEM, EDAX and TEM. The synthesized catalysts were screened in arylation (Heck reactions) and hydrogenation reactions of alkenes, and the results show that Pd(II)-DHBP@ SBA-15 exhibits high conversion and selectivity towards arylation and hydrogenation reactions of alkenes with high stability. The anchored solid catalysts can be recycled effectively and reused several times without major loss in activity.

1 aLazar, Anish1 aVinod, Chathakudath, P.1 aSingh, Anand, Pal uhttps://library.ncl.res.in/content/simple-phosphine-free-reusable-pdii-22-dihydroxybenzophenone-sba-15-catalyst-arylation-and01658nas a2200241 4500008004100000022001400041245013300055210006900188260000800257300001200265490000600277520079500283653002901078653001901107653002801126653002401154100002601178700001801204700001701222700002201239700002801261856012701289 2016 eng d a2365-654900aSynthesis of Au@Ni bimetallic core shell nanoparticle and nanochains in soyabean oil and their catalytic hydrogenation reactions0 aSynthesis of AuNi bimetallic core shell nanoparticle and nanocha cFEB a140-1460 v13 a

Synthesis of Au@Ni bimetallic core shell nanostructures using commercially available soya bean oil as the solvent through a sequential reduction strategy is reported. The energy efficiency and economic viability comes from the much milder temperatures and replacement of expensive and environmentally hazardous solvents like long chain organic amines and acids previously reported for synthesis. Thus, core shell nanoparticles having size regime of 10-15 nm with an excellent control over the nickel shell thickness (2 nm) over the gold core (8-10 nm) and Au@Ni nanochains is achieved. The synthesized materials are demonstrated to synergistically catalyze hydrogenation of nitro and C-C multiple bonds with much better efficiency as compared to individual nanoparticle counterparts.

10aBimetallic nanoparticles10aGold catalysis10ahydrogenation reactions10asynergistic effects1 aBharathan, Vysakh, A.1 aYadukiran, V.1 aLazar, Anish1 aSingh, Anand., P.1 aVinod, Chathakudath, P. uhttps://library.ncl.res.in/content/synthesis-auni-bimetallic-core-shell-nanoparticle-and-nanochains-soyabean-oil-and-their02314nas a2200205 4500008004100000245014500041210006900186260000800255490000700263520153500270100002101805700002601826700001701852700001801869700002801887700002501915700001601940700003001956856012201986 2018 eng d00aHighly stable COF-supported Co/Co(OH)(2) nanoparticles heterogeneous catalyst for reduction of nitrile/nitro compounds under mild conditions0 aHighly stable COFsupported CoCoOH2 nanoparticles heterogeneous c cSEP0 v143 aOrdered nanoporosity in covalent organic framework (COF) offers excellent opportunity for property development. Loading nanoparticles (nPs) onto them is one approach to introducing tailor-made properties into a COF. Here, a COF-Co/Co(OH)(2) composite containing about 16 wt% of <6 nm sized Co/Co(OH)(2) nPs is prepared on a N-rich COF support that catalyzes the release of theoretical equivalence of H-2 from readily available, safe, and cheap NaBH4. Furthermore, the released H-2 is utilized for the hydrogenation of nitrile and nitro compounds to amines under ambient conditions in a facile one-pot reaction. The COF "by choice" is built from "methoxy" functionalized dialdehydes which is crucial in enabling the complete retention of the COF structure under the conditions of the catalysis, where the regular Schiff bonds would have hydrolyzed. The N-rich binding pockets in the COF ensure strong nP-COF interactions, which provides stability and enables catalyst recycling. Modeling studies reveal the crucial role played by the COF in exposing the active facets and thereby in controlling the activation of the reducing agent. Additionally, via density functional theory, we provide a rational explanation for how these COFs can stabilize nanoparticles which grow beyond the limiting pore size of the COF and yet result in a truly stable heterogeneous catalyst - a ubiquitous observation. The study underscores the versatility of COF as a heterogeneous support for developing cheap and highly active nonnoble metal catalysts.1 aMullangi, Dinesh1 aChakraborty, Debanjan1 aPradeep, Anu1 aKoshti, Vijay1 aVinod, Chathakudath, P.1 aPanja, Soumendranath1 aNair, Sunil1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/highly-stable-cof-supported-cocooh2-nanoparticles-heterogeneous-catalyst-reduction01639nas a2200265 4500008004100000022001400041245011800055210006900173260000800242300001200250490000600262520069800268653002100966653001600987653001501003653001701018653001801035100003501053700003501088700003101123700003801154700002901192700002801221856012401249 2018 eng d a2199-692X00aMesoporous shell@macroporous core aluminosilicates as sustainable nanocatalysts for direct N-alkylation of amines0 aMesoporous shellmacroporous core aluminosilicates as sustainable cJUN a537-5410 v43 a

Aluminosilicate spheres with a macroporous core and mesoporous shell (Si/Al ratio of 11) is synthesised by a sol-gel method utilizing cetyltrimethyl ammonium bromide (CTAB) as a structure directing agent in basic medium. The selective incorporation of aluminium in the silica matrix results in the formation of aluminosilicates with an overall acidity of 0.32mmol/g with interconnected pores. Direct N-alkylation reaction is a prototype of C-N bond formation reaction and meso- macroporous aluminosilicate is shown to catalyze this reaction with excellent yield. The catalyst is tested and found sustainable for five catalytic cycles even without any high temperature regeneration step.

10aAluminosilicates10amacroporous10aMesoporous10aN-alkylation10ananocatalysis1 aSekhar, Anandakumari, C. Sunil1 aAshokkumar, Anumol, Erumpukuth1 aCygnet, Choorapoikayil, T.1 aLakshmi, Saseendranpillai, Vidhya1 aDeepak, Francis, Leonard1 aVinod, Chathakudath, P. uhttps://library.ncl.res.in/content/mesoporous-shellmacroporous-core-aluminosilicates-sustainable-nanocatalysts-direct-n02091nas a2200277 4500008004100000022001400041245017600055210006900231260000800300300001400308490000700322520109300329653001301422653002801435653001901463653001401482653002401496100002601520700002101546700001701567700002101584700002801605700002101633700002801654856013101682 2018 eng d a1867-388000aSelective oxidation of cyclohexane to cyclohexanone using chromium oxide supported mesoporous MCM-41 nanospheres: probing the nature of catalytically active chromium sites0 aSelective oxidation of cyclohexane to cyclohexanone using chromi cAUG a3291-32980 v103 a

Highly dispersed chromium oxide supported mesoporous MCM-41 nanosphere catalysts have been synthesized using a simple wet impregnation method. This work is devoted to a systematic study to reveal the active Cr sites in chromium oxide supported MCM-41 nanosphere catalysts for the selective oxidation of cyclohexane to cyclohexanone. To probe the nature of the active species, we synthesized 0.5-10wt% Cr loaded catalysts and characterized them by using XRD, UV/Vis spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, extended X-ray absorption fine structure analysis, X-ray absorption near edge structure analysis, N-2 sorption analysis, FTIR spectroscopy, (SiNMR)-Si-29 spectroscopy, SEM, and TEM. The liquid-phase oxidation of cyclohexane to cyclohexanone (99% selectivity) was performed under mild reaction conditions, and the results reveal clearly that the 5wt% Cr loaded catalyst was optimum for the reaction. The initial composition of isolated Cr3+ species in the catalyst is the major factor that influences the enhanced activity for cyclohexane oxidation.

10achromium10aheterogeneous catalysis10aNanostructures10aOxidation10asupported catalysts1 aBetsy, Kurisingal, J.1 aNayak, Chandrani1 aLazar, Anish1 aKrishnan, Athira1 aBhattacharyya, Dibyendu1 aJha, Shambhu, N.1 aVinod, Chathakudath, P. uhttps://library.ncl.res.in/content/selective-oxidation-cyclohexane-cyclohexanone-using-chromium-oxide-supported-mesoporous-mcm02337nas a2200253 4500008004100000022001400041245017500055210006900230260000800299300001600307490000600323520138600329100002601715700002201741700002701763700002101790700001701811700002301828700002101851700002801872700002401900700003001924856012901954 2019 eng d a2470-134300aCarbon derived from soft pyrolysis of a covalent organic framework as a support for small-sized RuO2 showing exceptionally low overpotential for oxygen evolution reaction0 aCarbon derived from soft pyrolysis of a covalent organic framewo cAUG a13465-134730 v43 a

Electrochemical water splitting is the most energy-efficient technique for producing hydrogen and oxygen, the two valuable gases. However, it is limited by the slow kinetics of the anodic oxygen evolution reaction (OER), which can be improved using catalysts. Covalent organic framework (COF)-derived porous carbon can serve as an excellent catalyst support. Here, we report high electrocatalytic activity of two composites, formed by supporting RuO2 on carbon derived from two COFs with closely related structures. These composites catalyze oxygen evolution from alkaline media with overpotentials as low as 210 and 217 mV at 10 mA/cm(2), respectively. The Tafel slopes of these catalysts (65 and 67 mV/dec) indicate fast kinetics compared to commercial RuO2. The observed activity is the highest among all RuO2-based heterogeneous OER catalysts-a touted benchmark OER catalyst. The high catalytic activity arises from the extremely small-sized (similar to 3-4 nm) RuO2 nanoparticles homogeneously dispersed in a micro-mesoporous (BET = 517 m(2)/g) COF-derived carbon. The porous graphenic carbon favors mass transfer, while its N-rich framework anchors the catalytic nanoparticles, making it highly stable and recyclable. Crucially, the soft pyrolysis of the COF enables the formation of porous carbon and simultaneous growth of small RuO2 particles without aggregation.

1 aChakraborty, Debanjan1 aNandi, Shyamapada1 aIllathvalappil, Rajith1 aMullangi, Dinesh1 aMaity, Rahul1 aSingh, Santosh, K.1 aHaldar, Sattwick1 aVinod, Chathakudath, P.1 aKurungot, Sreekumar1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/carbon-derived-soft-pyrolysis-covalent-organic-framework-support-small-sized-ruo2-showing02868nas a2200265 4500008004100000022001400041245015400055210006900209260000900278300001600287490000700303520188300310653002502193653003102218653003002249653002802279653002502307100002602332700002202358700002102380700002102401700002802422700003002450856012202480 2019 eng d a1944-824400aCu/Cu2O nanoparticles supported on a phenol-pyridyl COF as a heterogeneous catalyst for the synthesis of unsymmetrical diynes via glaser-hay coupling0 aCuCu2O nanoparticles supported on a phenolpyridyl COF as a heter cMAY  a15670-156790 v113 a

Covalent organic frameworks (COFs) are a new class of porous crystalline polymers with a modular construct that favors fiinctionalization. COF pores can be used to grow nanoparticles (nPs) with dramatic size reduction, stabilize them as dispersions, and provide excellent nP access. Embedding substrate binding sites in COFs can generate host-guest synergy, leading to enhanced catalytic activity. In this report, Cu/Cu2O nPs (2-3 nm) are grown on a COF, which is built by linking a phenolic trialdehyde and a triamine through Schiff bonds. Their micropores restrict the nP to exceptionally small sizes (similar to 2-3 nm), and the pore walls decorated with strategically positioned hydrogen-bonding phenolic groups anchor the substrates via hydrogen-bonding, whereas the basic pyridyl sites serve as cationic species to stabilize the [CuclusterCl2](2-) type reactive intermediates. This composite catalyst shows high activity for Glaser-Hay heterocoupling reactions, an essential 1,3-diyne yielding reaction with widespread applicability in organic synthesis and material science. Despite their broad successes in homocoupled products, preparation of unsymmetrical 1,3-diynes is challenging due to poor selectivity. Here, our COF-based Cu catalyst shows elevated selectivity toward heterocoupling product(s) (Cu nP loading 0.0992 mol %; turn over frequency: similar to 4S-50; turn over number: similar to 17S-190). The reversible redox activity at the Cu centers has been demonstrated by carrying out X-ray photoelectron spectroscopy on the frozen reactions, whereas the crucial interactions between the substrates and the binding sites in their optimized configurations have been modeled using density functional theory methods. This report emphasizes the utility of COFs in developing a heterogeneous catalyst for a truly challenging organic heterocoupling reaction.

10aCopper nanoparticles10aCovalent organic framework10aGlaser-Hay heterocoupling10aheterogeneous catalysis10aunsymmetrical diynes1 aChakraborty, Debanjan1 aNandi, Shyamapada1 aMullangi, Dinesh1 aHaldar, Sattwick1 aVinod, Chathakudath, P.1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/cucu2o-nanoparticles-supported-phenol-pyridyl-cof-heterogeneous-catalyst-synthesis01623nas a2200145 4500008004100000245012200041210006900163260000800232520100300240100002501243700002401268700002801292700002801320856012901348 2019 eng d00aMnO2@Fe3O4 Magnetic Nanoparticles as Efficient and Recyclable Heterogeneous Catalyst for Benzylic sp(3) C-H Oxidation0 aMnO2Fe3O4 Magnetic Nanoparticles as Efficient and Recyclable Het cSEP3 a

Herein, we report a highly chemoselective and efficient heterogeneous MnO2@Fe3O4 MNP catalyst for the oxidation of benzylic sp(3) C-H group of ethers using TBHP as a green oxidant to afford ester derivatives in high yield under batch/continuous flow module. This catalyst was also effective for the benzylic sp(3) C-H group of methylene derivatives to furnish the ketone in high yield which can be easily integrated into continuous flow condition for scale up. The catalyst is fully characterized by spectroscopic techniques and it was found that 0.424 % MnO2@Fe3O4 catalyzes the reaction; the magnetic nanoparticles of this catalyst could be easily recovered from the reaction mixture. The recovered catalyst was recycled for twelve cycles without any loss of the catalytic activity. The advantages of MnO2@Fe3O4 MNP are its catalytic activity, easy preparation, recovery, and recyclability, gram scale synthesis with a TOF of up to 14.93 h(-1) and low metal leaching during the reaction.

1 aPandey, Akanksha, M.1 aAgalave, Sandip, G.1 aVinod, Chathakudath, P.1 aGnanaprakasam, Boopathy uhttps://library.ncl.res.in/content/mno2fe3o4-magnetic-nanoparticles-efficient-and-recyclable-heterogeneous-catalyst-benzylic02288nas a2200325 4500008004100000022001400041245012100055210006900176260000900245300001600254490000600270520118200276653002401458653002801482653001901510653002101529653002801550653002201578653003701600100002201637700002601659700001601685700002401701700002401725700002001749700002801769700001901797700002401816856012201840 2020 eng d a2168-048500aBoron nitride and oxide supported on dendritic fibrous nanosilica for catalytic oxidative dehydrogenation of propane0 aBoron nitride and oxide supported on dendritic fibrous nanosilic cNOV  a16124-161350 v83 a

In this work, we were able to significantly increase the activity of boron nitride (BN) catalysts used for the oxidative dehydrogenation (ODH) of propane by designing and synthesizing BN supported on dendritic fibrous nanosilica (DFNS). DFNS/BN showed a markedly increased catalytic efficiency, accompanied by exceptional stability and selectivity. Textural characterization, together with solid-state nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopic analyses, indicates the presence of a combination of unique fibrous morphology of DFNS and various boron sites connected to silica to be the reason for this increase in the catalytic performance. Notably, DFNS/B2O3 also showed catalytic activity, although with more moderate selectivity compared to that of DFNS/BN. Solid-state NMR spectra indicate that the higher selectivity of DFNS/BN might stem from a larger amount of hydrogen-bonded hydroxyl groups attached to B atoms. This study indicates that both boron nitride and oxide are active catalysts and by using high surface area support (DFNS), conversion from propane to propene as well as productivity of olefins was significantly increased.

10aElectron microscopy10aheterogeneous catalysis10aNanostructures10aNMR spectroscopy10apropane dehydrogenation10aX-ray diffraction10aX-ray photoelectron spectroscopy1 aBelgamwar, Rajesh1 aRankin, Andrew, G. M.1 aMaity, Ayan1 aMishra, Amit, Kumar1 aGomez, Jennifer, S.1 aTrebosc, Julien1 aVinod, Chathakudath, P.1 aLafon, Olivier1 aPolshettiwar, Vivek uhttps://library.ncl.res.in/content/boron-nitride-and-oxide-supported-dendritic-fibrous-nanosilica-catalytic-oxidative02285nas a2200313 4500008004100000022001400041245011700055210006900172260000900241300001400250490000600264520120100270653002701471653003101498653002701529653002801556653001901584653001901603100002001622700002901642700002101671700002601692700002101718700001801739700002801757700002501785700003001810856013101840 2020 eng d a2574-097000aNanoporous covalent organic framework embedded with Fe/Fe3O4 nanoparticles as air-stable low-density nanomagnets0 aNanoporous covalent organic framework embedded with FeFe3O4 nano cSEP  a9088-90960 v33 a

Covalent organic frameworks (COFs) made of light atoms such as H, C, N, and O with a significant void-to-framework ratio are excellent low-density supports for nanoparticles (nPs). Their framework can be precoded with heteroatoms to ensure binding with metallic nanoclusters. With these advantages, if controlled amounts of magnetic nPs are anchored to them, they can yield low-density organic-inorganic nanomagnets. Their organic nature facilitates fusion with bulk materials such as paper/textile to enable bulk composites with well-dispersed low-density magnets, which have potential for defense and next-generation aviation applications. Herein, we have grown small Fe/Fe3O4 nPs (5-18 wt %) inside a COF. Interestingly, 300 mg of this organic-inorganic framework material (containing 50 mg of nPs) can lift a vial of similar to 15,000 mg (300 times heavier). Also, the hydrophobic COF wraps around the Fe/Fe3O4 nanocluster retaining its room-temperature magnetic character even after 1 year, while the naked nPs lose it within a few days because of air oxidation. Bulk composites with paper and polymers have been made using this low-density Fe-COF to demonstrate their processability.

10aair-stable nanomagnets10aCovalent organic framework10aFe/Fe3O4 nanoparticles10alow-density nanomagnets10amagnetic rayon10ananoporous COF1 aKushwaha, Rinku1 aKaleeswaran, Dhananjayan1 aHaldar, Sattwick1 aChakraborty, Debanjan1 aMullangi, Dinesh1 aBorah, Aditya1 aVinod, Chathakudath, P.1 aMurugavel, Ramaswamy1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/nanoporous-covalent-organic-framework-embedded-fefe3o4-nanoparticles-air-stable-low-density03575nas a2200205 4500008004100000022001400041245006600055210006400121260000900185300001200194490000700206520292200213100001903135700002803154700001803182700002103200700002803221700002403249856009603273 2021 eng d a1528-748300aCan we identify the salt-cocrystal continuum state using XPS?0 aCan we identify the saltcocrystal continuum state using XPS cFEB  a735-7470 v213 a

X-ray photoelectron spectroscopy (XPS) is used to understand the nature of acid-base crystalline solids, to know whether the product is a salt (proton transfer, O-center dot center dot center dot H-N+) or a cocrystal (neutral adduct, O-H center dot center dot center dot N). The present study was carried out to explore if intermediate states of proton transfer from COOH to nitrogen (the proton resides between hydrogen bonded to O and N, O center dot center dot center dot H center dot center dot center dot N, quasi state) can be differentiated from a salt (complete proton transfer, N+-H center dot center dot center dot center dot O-) and cocrystal (no proton transfer, O-H center dot center dot center dot N) using N 1s XPS spectroscopy. The intermediate states of proton transfer arise when the pK(a) difference between the acid and the conjugate base is between -1 and 4, -1 < Delta pK(a) < 4, a situation common with COOH and pyridine functional groups present in drug molecules and pharmaceutically acceptable coformers. Complexes of pyridine N bases with aromatic COOH molecules in nine salts/cocrystals were cocrystallized, and their N 1s core binding energies in XPS spectra were measured. The proton state was analyzed by single-crystal X-ray diffraction for confirmation. Three new complexes were crystallized and analyzed by XPS spectra (without knowledge of their X-ray structures), to assess the predictive ability of XPS spectra in differentiating salt-cocrystal intermediate states against the extremities. The XPS results were subsequently confirmed by single-crystal X-ray data. Complexes of 3,5-dinitrobenzoic acid and isonicotinamide in 1:1 and 1:2 ratios exist as a salt and a salt-cocrystal continuum, respectively, as shown by the N 1s core binding energies. The proton states of the crystalline solids by XPS are in good agreement with the corresponding crystal structures. Other complexes, such as those of 3,5-dinitrobenzoic acid with 1,2-bis(4-pyridyl)ethylene, exhibit a salt-cocrystal continuum, maleic acids with 1,2-bis(4-pyridyl)ethylene and acridine are salts, 2-hydroxybenzoic acid and acridine is a salt, and the complex of 3,5-dinitrobenzoic acid and 3-hydroxypyridine is a salt and salt-cocrystal continuum, while fumaric acids with 1,2-bis(4-pyridyl)ethylene and acridine are cocrystals. Furthermore, three new acidbase complexes of 3,5-dinitrobenzoic acid with phenazine, 4-hydroxypyridine, and 4-cyanopyridine were studied initially by XPS and then confirmed by X-ray diffraction. In summary, since the N 1s binding energies cluster in a narrow range as cocrystals (398.7-398.9 eV) and salts (400.1-401.1 eV), it is clearly possible to differentiate between cocrystals and salts, but the saltcocrystal continuum values in XPS spectra are clustered in an intermediate range of cocrystals and salts but overlap with those of cocrystal or salt binding energies.

1 aTothadi, Srinu1 aShaikh, Tabrez, Rafique1 aGupta, Sharad1 aDandela, Rambabu1 aVinod, Chathakudath, P.1 aNangia, Ashwini, K. uhttps://library.ncl.res.in/content/can-we-identify-salt-cocrystal-continuum-state-using-xps02884nas a2200205 4500008004100000022001400041245013900055210006900194260000900263300001400272490000700286520212500293100002202418700001602440700001602456700002302472700002802495700002402523856013102547 2021 eng d a2041-652000aLithium silicate nanosheets with excellent capture capacity and kinetics with unprecedented stability for high-temperature CO2 capture0 aLithium silicate nanosheets with excellent capture capacity and  cAPR  a4825-48350 v123 a

An excessive amount of CO2 is the leading cause of climate change, and hence, its reduction in the Earth's atmosphere is critical to stop further degradation of the environment. Although a large body of work has been carried out for post-combustion low-temperature CO2 capture, there are very few high temperature pre-combustion CO2 capture processes. Lithium silicate (Li4SiO4), one of the best known high-temperature CO2 capture sorbents, has two main challenges, moderate capture kinetics and poor sorbent stability. In this work, we have designed and synthesized lithium silicate nanosheets (LSNs), which showed high CO2 capture capacity (35.3 wt% CO2 capture using 60% CO2 feed gas, close to the theoretical value) with ultra-fast kinetics and enhanced stability at 650 degrees C. Due to the nanosheet morphology of the LSNs, they provided a good external surface for CO2 adsorption at every Li-site, yielding excellent CO2 capture capacity. The nanosheet morphology of the LSNs allowed efficient CO2 diffusion to ensure reaction with the entire sheet as well as providing extremely fast CO2 capture kinetics (0.22 g g(-1) min(-1)). Conventional lithium silicates are known to rapidly lose their capture capacity and kinetics within the first few cycles due to thick carbonate shell formation and also due to the sintering of sorbent particles; however, the LSNs were stable for at least 200 cycles without any loss in their capture capacity or kinetics. The LSNs neither formed a carbonate shell nor underwent sintering, allowing efficient adsorption-desorption cycling. We also proposed a new mechanism, a mixed-phase model, to explain the unique CO2 capture behavior of the LSNs, using detailed (i) kinetics experiments for both adsorption and desorption steps, (ii) in situ diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy measurements, (iii) depth-profiling X-ray photoelectron spectroscopy (XPS) of the sorbent after CO2 capture and (iv) theoretical investigation through systematic electronic structure calculations within the framework of density functional theory (DFT) formalism.

1 aBelgamwar, Rajesh1 aMaity, Ayan1 aDas, Tisita1 aChakraborty, Sudip1 aVinod, Chathakudath, P.1 aPolshettiwar, Vivek uhttps://library.ncl.res.in/content/lithium-silicate-nanosheets-excellent-capture-capacity-and-kinetics-unprecedented-stability01949nas a2200265 4500008004100000022001400041245010200055210006900157260000900226300001200235490000600247520110500253100002201358700001501380700001901395700002101414700001901435700001501454700002801469700001601497700001701513700000501530700002501535856012301560 2021 eng d a2380-819500aOperando generated ordered heterogeneous catalyst for the selective conversion of CO2 to methanol0 aOperando generated ordered heterogeneous catalyst for the select cFEB  a509-5160 v63 a

The discovery of new materials for efficient transformation of carbon dioxide (CO2) into desired fuel can revolutionize large-scale renewable energy storage and mitigate environmental damage due to carbon emissions. In this work, we discovered an operando generated stable Ni-In kinetic phase that selectively converts CO2 to methanol (CTM) at low pressure compared to the state-of-the-art materials. The catalytic nature of a well-known methanation catalyst, nickel, has been tuned with the introduction of inactive indium, which enhances the CTM process. The remarkable change in the mechanistic pathways toward methanol production has been mapped by operando diffuse reflectance infrared Fourier transform spectroscopy analysis, corroborated by first-principles calculations. The ordered arrangement and pronounced electronegativity difference between metals are attributed to the complete shift in mechanism. The approach and findings of this work provide a unique advance toward the next-generation catalyst discovery for going beyond the state-of-the-art in CO2 reduction technologies.

1 aCherevotan, Arjun1 aRaj, Jithu1 aDheer, Lakshay1 aRoy, Soumyabrata1 aSarkar, Shreya1 aDas, Risov1 aVinod, Chathakudath, P.1 aXu, Shaojun1 aWells, Peter1 a1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/operando-generated-ordered-heterogeneous-catalyst-selective-conversion-co2-methanol02165nas a2200253 4500008004100000022001400041245008400055210006900139260000800208300001500216490000700231520135000238653001601588653001701604653001101621653001701632100002201649700002201671700002601693700002101719700002801740700003001768856011301798 2022 eng d a1861-472800aCoordination flexibility aided CO2-specific gating in an iron isonicotinate MOF0 aCoordination flexibility aided CO2specific gating in an iron iso cFEB ae2021013050 v173 a

Coordination flexibility assisted porosity has been introduced into an Iron-isonicotinate metal-organic framework (MOF), (Fe(4-PyC)(2) . (OH). The framework showed CO2-specific gate opening behavior, which gets tuned as a function of temperature and pressure. The MOF ` s physisorptive porosity towards CO2, CH4, and N-2 was investigated; it adsorbed only CO2 via a gate opening phenomenon. The isonicotinate, representing a borderline soft base, is bound to the hard Fe3+ centre through monodentate carboxylate and pyridyl nitrogen. This moderately weak binding enables isonicotinate to spin like a spindle under the CO2 pressure opening the gate for a sharp increase in CO2 uptake at 333 mmHg (At 298 K, the CO2 uptake increases from 0.70 to 1.57 mmol/g). We investigated the MOF ` s potential for CO2/N-2 and CO2/CH4 gas separation aided by this gating. IAST model reveals that the CO2/N-2 selectivity jumps from 325 to 3131 when the gate opens, while the CO2/CH4 selectivity increases three times. Interestingly, this Fe-isonicotinate MOF did not follow the trend set by our earlier reported Hard-Soft Gate Control (established for isostructural M2+-isonicotinate MOFs (M=Mg, Mn)). However, we account for this discrepancy using the different oxidation state of metals confirmed by X-ray photoelectron spectroscopy and magnetism.

10aCO2 capture10aflexible MOF10agating10aIsonicotinic1 aSingh, Himan, Dev1 aNandi, Shyamapada1 aChakraborty, Debanjan1 aSingh, Kirandeep1 aVinod, Chathakudath, P.1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/coordination-flexibility-aided-co2-specific-gating-iron-isonicotinate-mof02813nas a2200229 4500008004100000022001400041245013100055210006900186260000800255300001600263490000700279520198000286100002302266700002202289700001802311700002202329700001702351700002602368700002802394700003002422856013102452 2022 eng d a2050-748800aCovalent organic framework with electrodeposited copper nanoparticles - a desirable catalyst for the Ullmann coupling reaction0 aCovalent organic framework with electrodeposited copper nanopart cJUL a15647-156560 v103 a

A covalent organic framework is a porous covalently-linked polymeric assembly built from molecular lego blocks, the monomers. A COF's high surface area, ordered pores, and intrinsic low density makes it a perfect heterogeneous catalyst component. Dispersing catalytic metal nanoparticles into the porous COF matrix in a `capping-agent-free' manner can aid the maximal utilization of the active sites. To generate single-site catalysts, metals have been anchored to dense supports, or metal ions have been coordinated to the porous organic framework. The latter has superior atom efficiency and a substrate diffusion advantage. Stably nestling neutral metallic clusters into open-framework supports with no specifically strong binding groups requires a different approach. If infused from extremely dilute electrolytes, metal clusters can be nanoconfined into electrically activated COFs. At low-loadings, it can resemble a single-site catalyst with high atom efficiency. Herein, we report the larger scale synthesis of IISERP-COF15 and electrochemical loading of copper nanoparticles into its pores at loadings as low as 3.34 wt%. We employed classical Ullmann reactions to adjudge its activity. Typical turnover numbers for the catalysts reported in the literature are approximately 50-100. A Cu@COF shows high activity with a very low catalyst loading of 0.25 mol% (TON around similar to 300-350 vs. 4 for neat CuCl2 center dot 2H(2)O (homogeneous catalyst) and turnover frequency (similar to 15-17 h(-1))). We recycled it for up to 3 cycles. Furthermore, we report a multi-fold Ullmann reaction producing an unreported hexaaldehyde to demonstrate the latitude of the catalyst. Our work points to the potential of a dilutely loaded metal@COF as a mimic of the single-site catalyst for synthesizing valuable C-O linked molecules. Our findings from computational modeling shed light on the role of the COF as an active nanoporous support for Ullmann C-O coupling.

1 aChandran, Chandana1 aSingh, Himan, Dev1 aLeo, Liya, S.1 aShekhar, Pragalbh1 aRase, Deepak1 aChakraborty, Debanjan1 aVinod, Chathakudath, P.1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/covalent-organic-framework-electrodeposited-copper-nanoparticles-desirable-catalyst-ullmann01989nas a2200193 4500008004100000022001400041245014000055210006900195260000900264300001400273490000700287520127000294100001501564700001601579700001501595700002801610700002501638856013201663 2022 eng d a1754-569200aGreen transformation of CO2 to ethanol using water and sunlight by the combined effect of naturally abundant red phosphorus and Bi2MoO60 aGreen transformation of CO2 to ethanol using water and sunlight  cMAY  a1967-19760 v153 a

Direct photocatalytic conversion of CO2 to ethanol remains a scientific challenge because of the sluggish kinetics of C-C coupling and complex multielectron transfer processes. To achieve a green transformation of CO2 to C1+ products using naturally abundant sunlight and water requires the smart design of an efficient catalyst by selecting the right combination of atoms either in elemental or in compound form. Herein, we report a composite photocatalyst composed of earth abundant red phosphorus (RP) in nano-sheet morphology decorated with Bi2MoO6 nano-particles. The composite synthesised by a facile ultrasonication method produces 51.8 mu mol g(-1) h(-1) of ethanol from CO2. The ability of RP for the conversion of CO2 to C1 has been altered by the introduction of Bi2MoO6. In situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) and Kinetic Isotopic Effect (KIE) analysis shed light on the mechanistic pathway, which propose that the presence of Bi-Mo dual sites play a crucial role in the C-C coupling toward the formation of ethanol. Spectroscopic evidence and isotope labeling experiments suggest that the intermediate OCH3* is the key active species for ethanol formation via self-coupling followed by proton transfer.

1 aDas, Risov1 aDas, Kousik1 aRay, Bitan1 aVinod, Chathakudath, P.1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/green-transformation-co2-ethanol-using-water-and-sunlight-combined-effect-naturally-abundant02471nas a2200301 4500008004100000022001400041245011900055210006900174260000800243300001600251490000700267520146700274653001401741653003601755653001801791653000801809653001801817100002501835700002201860700002001882700002201902700001501924700002801939700002501967700002001992700002902012856012802041 2022 eng d a1944-824400aImprovement in oxygen evolution performance of NiFe layered double hydroxide grown in the presence of 1T-Rich MoS20 aImprovement in oxygen evolution performance of NiFe layered doub cJUL a31951-319610 v143 a

NiFe layered double hydroxide (NiFe LDH) grown in the presence of MoS2 (rich in 1T phase) shows exceptional performance metrics for alkaline oxygen evolution reaction (OER) in this class of composites. The as-prepared NiFe LDH/MoS2 composite (abbreviated as MNF) exhibits a low overpotential (eta(10)) of 190 mV; a low Tafel slope of 31 mV dec(-1); and more importantly, a high stability in its performance manifested by the delivery of current output for 45 h. It is important to note that this could be achieved with an exceedingly low loading of 0.14 mg cm(-2). The mass activity of this composite (97 A g(-1)) is about 14 times greater than that of the conventional RuO2 (7 A g(-1) ) at eta = 200 mV. When normalized with respect to the total metal content, a mass activity of 1000 A g(-1) (eta = 300 mV) was achieved. Impedance analysis further reveals that the significant reduction in charge-transfer resistance and hence high current density (5 times greater as compared to NiFe LDH at eta = 300 mV) observed for MNF is associated with interfacial adsorption kinetics of intermediates (R-1). Significant enhancement in the intrinsic activity of MNF over LDH has been observed through normalization of current with the electrochemically active surface area. Computational studies suggest that the Ni centers in the composite act as the active sites for OER, which is well-corroborated with the observed postreaction appearance of Ni3+ species.

10aImpedance10aLDH-MoS2 hybrid electrocatalyst10amass activity10aOER10aoverpotential1 aChakraborty, Soumita1 aMarappa, Shivanna1 aAgarwal, Sakshi1 aBagchi, Debabrata1 aRao, Ankit1 aVinod, Chathakudath, P.1 aPeter, Sebastian, C.1 aSingh, Abhishek1 aEswaramoorthy, Muthusamy uhttps://library.ncl.res.in/content/improvement-oxygen-evolution-performance-nife-layered-double-hydroxide-grown-presence-1t01967nas a2200265 4500008004100000022001400041245009200055210006900147260000800216300001100224490000800235520109700243653002001340653001101360653003001371653002401401100002201425700001501447700002901462700002101491700002201512700002801534700002501562856011401587 2022 eng d a0926-337300aInfluence of support textural property on CO2 to methane activity of Ni/ SiO2 catalysts0 aInfluence of support textural property on CO2 to methane activit cNOV a1216920 v3173 a

In this work, we elucidated the role of physicochemical textural properties of inert support on the catalyst ac-tivity by impregnating Ni on ordered mesoporous silica (SBA-15 and MCM-41) and non-mesoporous silica (nMPS). The catalyst Ni/SBA-15 exhibited the best CO2 conversion (83%) and product selectivity (99.9 %) followed by Ni/MCM-41 and the least by Ni/nMPS. The difference in the nature of the catalyst, degree of nanoparticle distribution and nanoparticle encapsulation by different silica support were studied by N2 adsorption-desorption and X-ray photoelectron spectroscopy (XPS) experiments. The Operando Diffused Reflec-tance Infrared Fourier Transform Spectroscopy were used to understand the variance in reaction pathway which is accredited to the textural properties of the support. The SBA-15 supported Ni catalyst followed dissociative CO pathway while MCM-41 and nMPS reacted through associative formate mechanism as major pathway. These findings provide a novel perspective on CO2 hydrogenation over Ni-silica, allowing us to tune both activity and selectivity.

10aCO2 methanation10aDRIFTS10aMesoporous silica support10aTextural properties1 aCherevotan, Arjun1 aRay, Bitan1 aChuripard, Sathyapal, R.1 aKaur, Komalpreet1 aGautam, Ujjal, K.1 aVinod, Chathakudath, P.1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/influence-support-textural-property-co2-methane-activity-ni-sio2-catalysts02500nas a2200301 4500008004100000022001400041245012000055210006900175260000900244300001200253490000700265520151200272653001801784653002001802653001201822653001901834653001301853100001501866700001901881700001801900700002801918700002201946700002001968700002801988700002702016700002502043856013002068 2022 eng d a2155-543500aNoble-metal-free heterojunction photocatalyst for selective CO2 reduction to methane upon induced strain relaxation0 aNoblemetalfree heterojunction photocatalyst for selective CO2 re cJAN  a687-6970 v123 a

Sunlight-driven CO2 hydrogenation has drawn tremendous attention. However, selective CH4 formation via CO2 photoreduction is very challenging. Herein, we report a metal oxide semiconductor heterojunction consisting of BiVO4 and WO3 as a photocatalyst for the efficient conversion of carbon dioxide (CO2) selectively to methane (105 mu mol g(-1) h(-1)) under visible light in the absence of a sacrificial agent. Wise selection of the reaction medium and the strategically tuned heterojunction upon strain relaxation suppresses the competitive hydrogen generation reaction. The detailed photophysical, photoelectrochemical, and X-ray absorption spectroscopy studies pointed to the Z-scheme mechanism of electron transfer, which favors superior electron and hole separation compared to the individual components of the composite catalyst and other well-known photocatalysts reported for CO2 reduction. The observations are further corroborated by experimental diffuse reflectance infrared Fourier transform spectroscopy and theoretical density-functional theory calculations, which reveal that the heterojunction has a lower free-energy barrier for CO2 conversion to CH4 due to the larger stabilization of the *CH2O intermediate on the strain-relaxed heterojunction surface, in comparison to the pristine BiVO4 surface. The present work provides fundamental insights for constructing high-performance heterojunction photocatalysts for the selective conversion of CO2 to desired chemicals and fuels.

10aCO2 reduction10aheterostructure10amethane10aPhotocatalysis10aZ-scheme1 aDas, Risov1 aSarkar, Shreya1 aKumar, Ritesh1 aRamarao, Seethiraju, D.1 aCherevotan, Arjun1 aJasil, Mohammed1 aVinod, Chathakudath, P.1 aSingh, Abhishek, Kumar1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/noble-metal-free-heterojunction-photocatalyst-selective-co2-reduction-methane-upon-induced02437nas a2200253 4500008004100000022001400041245012400055210006900179260000800248300001400256490000700270520155500277653001801832653002101850653003001871653002201901653001701923100002201940700001901962700002701981700002802008700002502036856012202061 2022 eng d a1936-085100aPotential- and time-dependent dynamic nature of an oxide-derived pdin nanocatalyst during electrochemical CO2 reduction0 aPotential and timedependent dynamic nature of an oxidederived pd cAPR a6185-61960 v163 a

Electrochemical reduction of CO2 into valuable fuels and chemicals is a promising route of replacing fossil fuels by reducing CO2 emissions and minimizing its adverse effects on the climate. Tremendous efforts have been carried out for designing efficient catalyst materials to selectively produce the desired product in high yield from CO2 by the electrochemical process. In this work, a strategy is reported to enhance the electrochemical CO2 reduction reaction (ECO2RR) by constructing an interface between a metal-based alloy (PdIn) nanoparticle and an oxide (In2O3), which was synthesized by a facile solution method. The oxide-derived PdIn surface has shown excellent eCO(2)RR activity and enhanced CO selectivity with a Faradaic efficiency (FE) of 92.13% at -0.9 V (vs RHE). On the other hand, surface PdO formation due to charge transfer on the bare PdIn alloy reduces the CO2RR activity. With the support of in situ (EXAFS and IR) and ex situ (XPS, Raman) spectroscopic techniques, the optimum presence of the Pd-In-O interface has been identified as a crucial parameter for enhancing eCO(2)RR toward CO in a reducing atmosphere. The influence of eCO(2)RR duration is reported to affect the overall performance by switching the product selectivity from H-2 (from water reduction) to CO (from eCO(2)RR) on the oxide-derived alloy surface. This work also succeeded in the multifold enhancement of the current density by employing the gas diffusion electrode (GDE) and optimizing its process parameters in a flow cell configuration.

10aCO2 reduction10aElectrochemistry10aheterostructure interface10ain situ mechanism10ananocatalyst1 aBagchi, Debabrata1 aSarkar, Shreya1 aSingh, Ashutosh, Kumar1 aVinod, Chathakudath, P.1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/potential-and-time-dependent-dynamic-nature-oxide-derived-pdin-nanocatalyst-during02397nas a2200277 4500008004100000022001400041245017600055210006900231260000800300300001600308490000700324520139600331100002201727700001501749700001701764700002201781700002701803700001601830700002901846700001701875700002101892700002201913700002801935700002501963856013101988 2022 eng d a2050-748800aTuning the hybridization and charge polarization in metal nanoparticles dispersed over Schiff base functionalized SBA-15 enhances CO2 capture and conversion to formic acid0 aTuning the hybridization and charge polarization in metal nanopa cSEP a18354-183620 v103 a

Different Schiff base functionalized SBA-15 materials were synthesized through condensation reactions between 3-aminopropyltriethoxysilane (APTES) and different aldehydes (glutaraldehyde and butyraldehyde) over a mesoporous silica, SBA-15 (APTES-GLU/SBA-15 and APTES-BUT/SBA-15). Both static and dynamic experiments have been used for testing the CO2 capture efficiency of these materials. The hybridization of the N atom in APTES has been tuned from sp(3) to sp(2) upon condensation facilitating optimum CO2 capture in the direct synthesis of APTES-GLU/SBA-15. The undesirable oxides of nitrogen have been removed during the synthesis process to improve the CO2 capture efficiency. These materials were employed as supports for Pd-Ag and Pd-Ni bimetallic systems for the selective conversion of the captured CO2 to formic acid (FA) in 0.5 M KHCO3 solution. The Pd-Ni catalyst system exhibited enhanced CO2 to FA conversion activity compared to other heterogeneous systems, which is similar to 4 times better than that of the Pd-Ag system in this study. The X-ray absorption studies over the catalyst material confirmed that the relatively electron-deficient Ni in Pd-Ni compared to Ag in Pd-Ag favoured higher charge polarization between the metals in the Pd-Ni system enhancing the CO2 to FA conversion. The experimental observations are well supported by the DFT calculations.

1 aCherevotan, Arjun1 aRay, Bitan1 aYadav, Anish1 aBagchi, Debabrata1 aSingh, Ashutosh, Kumar1 aRiyaz, Mohd1 aChuripard, Sathyapal, R.1 aNaral, Vinay1 aKaur, Komalpreet1 aGautam, Ujjal, K.1 aVinod, Chathakudath, P.1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/tuning-hybridization-and-charge-polarization-metal-nanoparticles-dispersed-over-schiff-base03019nas a2200301 4500008004100000022001400041245014600055210006900201260000900270300001600279490000700295520196300302653000902265653003202274653001802306653002302324653003802347653003002385653002502415100001802440700001602458700002202474700002002496700002702516700002802543700002502571856012102596 2023 eng d a1936-085100aDistortion-induced interfacial charge transfer at single cobalt atom secured on ordered intermetallic surface enhances pure oxygen production0 aDistortioninduced interfacial charge transfer at single cobalt a cNOV  a23169-231800 v173 a

In this work, atomic cobalt (Co) incorporation into the Pd2Ge intermetallic lattice facilitates operando generation of a thin layer of CoO over Co-substituted Pd2Ge, with Co in the CoO surface layer functioning as single metal sites. Hence the catalyst has been titled Co-1-CoO-Pd2Ge. High-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy confirm the existence of CoO, with some of the Co bonded to Ge by substitution of Pd sites in the Pd2Ge lattice. The role of the CoO layer in the oxygen evolution reaction (OER) has been verified by its selective removal using argon sputtering and conducting the OER on the etched catalyst. In situ X-ray absorption near-edge structure and extended X-ray absorption fine structure spectroscopy demonstrate that CoO gets transformed to CoOOH (Co3+) in operando condition with faster charge transfer through Pd atoms in the core Pd2Ge lattice. In situ Raman spectroscopy depicts the emergence of a CoOOH phase on applying potential and shows that the phase is stable with increasing potential and time without getting converted to CoO2. Density functional theory calculations indicate that the Pd2Ge lattice induces distortion in the CoO phase and generates unpaired spins in a nonmagnetic CoOOH system resulting in an increase in the OER activity and durability. The existence of spin density even after electrocatalysis is verified from electron paramagnetic resonance spectroscopy. We have thus successfully synthesized intermetallic supported CoO during synthesis and rigorously verified the role played by an intermetallic Pd2Ge core in enhancing charge transfer, generating spin density, improving electrochemical durability, and imparting mechanical stability to a thin CoOOH overlayer. Differential electrochemical mass spectrometry has been explored to visualize the instantaneous generation of oxygen gas during the onset of the reaction.

10aDEMS10ainterfacial charge transfer10aIntermetallic10along-termstability10aoperando spectroscopic techniques10aOxygen Evolution Reaction10astructuraldistortion1 aMondal, Soumi1 aRiyaz, Mohd1 aBagchi, Debabrata1 aDutta, Nilutpal1 aSingh, Ashutosh, Kumar1 aVinod, Chathakudath, P.1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/distortion-induced-interfacial-charge-transfer-single-cobalt-atom-secured-ordered02564nas a2200289 4500008004100000022001400041245013800055210006900193260000800262490000700270520158500277653001701862653002401879653001801903653001201921653001901933100001601952700001501968700001601983700001601999700002202015700002702037700002702064700002802091700002502119856013002144 2023 eng d a0935-964800aIntrinsic charge polarization in Bi19S27Cl3 nanorods promotes selective C-C coupling reaction during photoreduction of CO2 to ethanol0 aIntrinsic charge polarization in Bi19S27Cl3 nanorods promotes se cFEB0 v353 a

Obtaining multi-carbon products via CO2 photoreduction is a major catalytic challenge involving multielectron-mediated C-C bond formation. Complex design of multicomponent interfaces that are exploited to achieve this chemical transformation, often leads to untraceable deleterious changes in the interfacial chemical environment affecting CO2 conversion efficiency and product selectivity. Alternatively, robust metal centers having asymmetric charge distribution can effectuate C-C coupling reaction through the stabilization of intermediates, for desired product selectivity. However, generating inherent charge distribution in a single component catalyst is a difficult material design challenge. Here, a novel photocatalyst, Bi19S27Cl3, is presented which selectively converts CO2 to a C-2 product, ethanol, in high yield under visible light irradiation. Structural analysis through transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy reveals the presence of charge polarized bismuth centers in Bi19S27Cl3. The intrinsic electric field induced by charge polarized bismuth centers renders better separation efficiency of photogenerated electron-hole pair. Furthermore, charge polarized centers yield better adsorption of CO* intermediate and accelerate the rate determining C-C coupling step through the formation of OCCOH intermediate. Formation of these intermediates is experimentally mapped by in situ Fourier-transform infrared spectroscopy and further confirmed by theoretical calculation.

10aC-C coupling10acharge polarization10aCO2 reduction10aEthanol10aPhotocatalysis1 aDas, Kousik1 aDas, Risov1 aRiyaz, Mohd1 aParui, Arko1 aBagchi, Debabrata1 aSingh, Ashutosh, Kumar1 aSingh, Abhishek, Kumar1 aVinod, Chathakudath, P.1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/intrinsic-charge-polarization-bi19s27cl3-nanorods-promotes-selective-c-c-coupling-reaction01616nas a2200181 4500008004100000022001400041245008200055210006900137260000900206300001400215490000700229520098500236100002301221700002801244700002101272700003201293856010901325 2023 eng d a0888-588500aWadsworth-emmons reaction by using the fluorapatite catalyst: kinetic studies0 aWadsworthemmons reaction by using the fluorapatite catalyst kine cMAY  a7901-79110 v623 a

Wadsworth-Emmons reaction was successfully carriedout byusing the fluorapatite (FAP) catalyst. The reaction of 2-methoxybenzaldehydeand triethylphosphonoacetate using FAP afforded & alpha;,& beta;-unsaturatedester with 100% conversion and 80% selectivity. A kinetic model wasvalidated at different temperatures by Langmuir-Hinshelwood-Hougen-Watson(LHHW), and the absence of mass transfer resistance was verified bythe Weisz Prater criterion. The effect of different catalysts, temperature,catalyst loading, solvent, mole ratio, and speed of stirring was studied.The FAP catalyst was characterized by Fourier transform infrared spectroscopy,Brunauer-Emmett-Teller method, nitrogen adsorption-desorption,transmission electron microscopy, energy-dispersive X-ray spectroscopy,temperature programmed desorption (TPD-NH3), X-ray diffraction,and X-ray photoelectron spectroscopy. The FAP catalyst was found tobe stable up to three recycles with no loss in activity.

1 aVishwakarma, Rakhi1 aVinod, Chathakudath, P.1 aRathod, Virendra1 aKantam, Mannepalli, Lakshmi uhttps://library.ncl.res.in/content/wadsworth-emmons-reaction-using-fluorapatite-catalyst-kinetic-studies01871nas a2200265 4500008004100000022001400041245011700055210006900172260001100241490000700252520097200259653001701231653002401248653001801272653001901290100002601309700001501335700001601350700001601366700002701382700002201409700002801431700002501459856012101484 2023 eng d a1433-785100aWurtzite CuGaS2 with an in-situ-formed CuO layer photocatalyzes CO2 conversion to ethylene with high selectivity0 aWurtzite CuGaS2 with an insituformed CuO layer photocatalyzes CO cFEB 200 v623 a

We present surface reconstruction-induced C-C coupling whereby CO2 is converted into ethylene. The wurtzite phase of CuGaS2. undergoes in situ surface reconstruction, leading to the formation of a thin CuO layer over the pristine catalyst, which facilitates selective conversion of CO2 to ethylene (C2H4). Upon illumination, the catalyst efficiently converts CO2 to C2H4 with 75.1 % selectivity (92.7 % selectivity in terms of R-electron) and a 20.6 mu mol g(-1) h(-1) evolution rate. Subsequent spectroscopic and microscopic studies supported by theoretical analysis revealed operando-generated Cu2+, with the assistance of existing Cu+, functioning as an anchor for the generated *CO and thereby facilitating C-C coupling. This study demonstrates strain-induced in situ surface reconstruction leading to heterojunction formation, which finetunes the oxidation state of Cu and modulates the CO2 reduction reaction pathway to selective formation of ethylene.

10aC-C coupling10acharge polarization10aCO2 reduction10aPhotocatalysis1 aChakraborty, Subhajit1 aDas, Risov1 aRiyaz, Mohd1 aDas, Kousik1 aSingh, Ashutosh, Kumar1 aBagchi, Debabrata1 aVinod, Chathakudath, P.1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/wurtzite-cugas2-situ-formed-cuo-layer-photocatalyzes-co2-conversion-ethylene-high01719nas a2200229 4500008004100000022001400041245008100055210006900136260000800205490000700213520097500220653001201195653001801207653002501225653001101250653001301261100002301274700002801297700002501325700003201350856010701382 2024 eng d a1867-388000aHydrogenation of glucose to sorbitol by using nickel hydroxyapatite catalyst0 aHydrogenation of glucose to sorbitol by using nickel hydroxyapat cMAY0 v163 a

A series of nickel hydroxyapatite catalysts were synthesized by the co-precipitation method followed by calcination and reduction. These catalysts were employed for the aqueous phase hydrogenation of glucose to sorbitol. The Ni-HAP catalyst with comparatively high surface area and acid-base strength gave high sorbitol selectivity in 1 h. Ni-HAP-4 catalyst with moderate Ni (3.5 wt. %) content having smaller and highly dispersed nickel particles gives an excellent yield of sorbitol, 97 % in 1 h. The Ni-HAP-4 catalyst works well with other polar protic solvents. Different characterization techniques like XRD, TEM, SEM-EDS, BET, NH3-TPD, and CO2-TPD were employed to analyze the Ni-HAP-4 catalyst. A facile hydrogenation of glucose to sorbitol has been reported with Ni-HAP catalyst using water as a solvent. The excellent yield of sorbitol, 97 % in 1 h is possible due to the high surface area and high acid-base strength of the Ni-HAP-4 catalyst. image

10aglucose10aHydrogenation10aHydroxyapatite (HAP)10aNickel10aSorbitol1 aKamble, Paresh, A.1 aVinod, Chathakudath, P.1 aRathod, Virendra, K.1 aKantam, Mannepalli, Lakshmi uhttps://library.ncl.res.in/content/hydrogenation-glucose-sorbitol-using-nickel-hydroxyapatite-catalyst02627nas a2200277 4500008004100000022001400041245011400055210006900169260000800238300001400246490000700260520169300267653003001960653002401990653002002014653002002034653001902054653001702073100003202090700001902122700001702141700001702158700002802175700002302203856012302226 2024 eng d a2155-543500aPhotocatalytic regeneration of reactive cofactors with inP quantum dots for the continuous chemical synthesis0 aPhotocatalytic regeneration of reactive cofactors with inP quant cAPR a6740-67480 v143 a

The shuttling of redox-active nicotinamide cofactors between the light and dark cycles is the key to the continuous production of biomass in photosynthesis. The replication of such processes in artificial photosynthetic systems demands fast photoregeneration as well as simultaneous integration of these nicotinamide cofactors into the dark cycle. Here, we report the design of an artificial photosynthetic system for the continuous production of butanol via the constant photoregeneration and consumption of nicotinamide cofactors, powered by an indium phosphide quantum dot (InP QD) photocatalyst and alcohol dehydrogenase (ADH) enzyme, respectively. A strong electrostatic attraction between the oppositely charged InP QDs and electron mediators significantly enhanced the charge extraction and utilization processes, enabling a fast (similar to 30 min, with a turn over frequency of similar to 1333 h(-1)), quantitative (>99%), and selective photoregeneration of enzymatically active nicotinamide cofactors in the light cycle. These photoregenerated nicotinamide cofactors were further coupled in the dark cycle to trigger the ADH oxidoreductase enzyme for the production of butanol, via sequential as well as simultaneous light-dark cycles. The amount of butanol produced under simultaneous light-dark cycles was higher than the stoichiometric limit, proving the constant regeneration and consumption of nicotinamide cofactors in light and dark cycles, respectively. Thus, a proper design and integration of the InP QD-based photocatalytic cycle with the enzymatic cycle led to the effective electron shuttling between light and dark cycles, as seen in photosynthesis.

10aartificial photosynthesis10abiologicalcofactors10acharge transfer10aindiumphosphide10aPhotocatalysis10aquantum dots1 aChakraborty, Indra, Narayan1 aJain, Vanshika1 aRoy, Pradyut1 aKumar, Pawan1 aVinod, Chathakudath, P.1 aPillai, Pramod, P. uhttps://library.ncl.res.in/content/photocatalytic-regeneration-reactive-cofactors-inp-quantum-dots-continuous-chemical02271nas a2200229 4500008004100000022001400041245012400055210006900179260000900248300001400257490000700271520145500278100002201733700001601755700001501771700002101786700002701807700002201834700002801856700002501884856013201909 2024 eng d a0897-475600aUnraveling the cooperative mechanisms in ultralow copper-loaded WC@NGC for enhanced CO2 electroreduction to acetic acid0 aUnraveling the cooperative mechanisms in ultralow copperloaded W cMAR  a3464-34760 v363 a

Electrochemical CO2 reduction reaction (eCO(2)RR) has been explored on tungsten carbide (WC) nanoparticles embedded on N-doped graphitic carbon (NGC), demonstrating excellent activity toward the formation of acetic acid at an extremely lower potential. The activity has been further enhanced by loading ultralow copper sites into the catalyst system, exhibiting 80.02% Faradaic efficiency (FE) toward acetic acid at an applied potential of -0.3 V (vs RHE). Potential-dependent in situ infrared (IR), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, ex situ extended X-ray absorption fine structure (EXAFS) studies, and computational analysis confirm that synergy between uniformly dispersed Cu atoms and WC lattice plays a crucial role in the formation of acetic acid with high FE at a lower potential. It has been observed that the W atom of WC strongly chemisorbs CO2 with a significant change in the C-O bond length and the O-C-O bond angle, in contrast to weaker adsorption on Cu-based catalyst surfaces. The presence of a Cu site enhances the adsorption of CO2, thereby increasing the possibility of C-C coupling kinetically. Most importantly, hydrogen evolution predominates on the catalyst's surface at higher applied potentials (-0.5 to -1.1 V vs RHE), elucidating the mechanism underlying enhanced charge transfer between copper and WC, a phenomenon ascertained through in situ IR spectroscopy and ex situ XPS analysis

1 aBagchi, Debabrata1 aRiyaz, Mohd1 aRaj, Jithu1 aRoy, Soumyabrata1 aSingh, Ashutosh, Kumar1 aCherevotan, Arjun1 aVinod, Chathakudath, P.1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/unraveling-cooperative-mechanisms-ultralow-copper-loaded-wcngc-enhanced-co2-electroreduction02464nas a2200325 4500008004100000245014900041210006900190260000800259300001500267490000700282520139000289653001501679653001501694653001801709653001101727653001601738653001901754100001601773700002601789700001901815700002701834700001501861700001801876700001601894700001901910700002001929700002801949700002501977856013602002 2025 eng d00aDopant and exfoliation induced simultaneous modification of charge density and C―C coupling sites for efficient CO2 photoreduction to ethylene0 aDopant and exfoliation induced simultaneous modification of char cJUL ae2024234710 v643 a

The photochemical conversion of CO2 into C2+ products has emerged as an attractive method for synthesizing valuable chemicals and fuels using abundant solar energy. However, the challenge lies in enhancing the efficiency and selectivity of C2+ product formation. In this study, we employed a heteroatom doping strategy to optimize the photocatalytic parameters and achieve excellent efficiency and selectivity in the photocatalytic CO2 reduction to C2+ product formation. Our experimental analysis revealed that the local electronic structure of the catalyst, modified by In-doping, enables enhanced efficiency. Additionally, the incorporation of Cu facilitates the coupling of C1 intermediates, resulting in excellent selectivity towards C2+ products. The CO2 reduction performance is further enhanced through exfoliation, which increases the exposure of active sites and extends the charge carrier lifetime by reducing the charge diffusion length. We report that the rate of formation of C2H4 reached 54.3 mu molh(-1)g(-1) with an outstanding selectivity of 91% over the exfoliated CuIn-doped AgBiP2S6 catalyst. By elucidating the role of heteroatom doping and exfoliation in enhancing both the efficiency and selectivity of C2+ product formation, our study contributes to advancing the development of sustainable and efficient photocatalytic CO2 conversion technologies.

10aC & horbar10aC coupling10aCO2 reduction10aDoping10aExfoliation10aPhotocatalysis1 aDas, Kousik1 aChakraborty, Subhajit1 aKediya, Siddhi1 aSingh, Ashutosh, Kumar1 aDas, Risov1 aMondal, Soumi1 aRiyaz, Mohd1 aGoud, Devender1 aDutta, Nilutpal1 aVinod, Chathakudath, P.1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/dopant-and-exfoliation-induced-simultaneous-modification-charge-density-and-c%E2%80%95c-coupling01876nas a2200241 4500008004100000022001400041245017500055210006900230260000800299300001400307490000700321520097300328100002201301700002701323700001701350700003001367700001501397700002101412700001901433700002801452700002501480856012901505 2025 eng d a2050-748800aMetal deficiency tuned charge transfer in intermetallic Ni2-xSn (x =0.37-0.65) enhances selective conversion of furfural to furfuryl alcohol towards the theoretical limit0 aMetal deficiency tuned charge transfer in intermetallic Ni2xSn x cFEB a6042-60480 v133 a

Heterogeneous catalysis facilitated by intermetallic nanoparticles has recently been the subject of increased scrutiny, given the enhanced selectivity and stability they bestow on many chemical reactions compared to their monometallic components. This paper explores a series of Ni-Sn (Ni2-xSn, where x = 0.65, 0.5, 0.37) intermetallic compounds supported on a high-surface-area support, SBA-15, as catalysts for the selective hydrogenation of furfural to furfuryl alcohol. Rietveld refinements of the X-ray diffraction data show catalysts with mixed intermetallic phases that assist in the catalysis. At the same time, X-ray photoelectron spectroscopy (XPS) studies and X-ray absorption studies indicate the role played by charge transfer from Sn to Ni for the catalysis. Selectivity to the desired furfuryl alcohol in all the intermetallic samples was high (>97%), but Ni1.35Sn had a relatively lower conversion than the other intermetallic compounds.

1 aCherevotan, Arjun1 aSingh, Ashutosh, Kumar1 aYadav, Anish1 aMaligal-Ganesh, Raghu, V.1 aRaj, Jithu1 aPulparambil, Anu1 aGoud, Devender1 aVinod, Chathakudath, P.1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/metal-deficiency-tuned-charge-transfer-intermetallic-ni2-xsn-x-037-065-enhances-selective01345nas a2200193 4500008004100000022001400041245009000055210006900145260000800214300001600222490000700238520065800245100002500903700002300928700002800951700002500979700003201004856011501036 2025 eng d a1477-922600aSynthesis of 5-hydroxymethylfurfural from glucose using a tert-butoxyapatite catalyst0 aSynthesis of 5hydroxymethylfurfural from glucose using a tertbut cSEP a13574-135870 v543 a

In this study, 5-hydroxymethylfurfural (5-HMF) was obtained from glucose using tert-butoxyapatite, a heterogeneous catalyst. The tert-butoxyapatite catalyst was prepared and characterized by several techniques, such as XRD, SEM, TEM, EDS, elemental mapping HR-TEM, N2-adsorption/desorption, XPS, and FT-IR. Several parameters were studied, such as temperature, catalyst loading, and glucose concentration. The tert-butoxyapatite catalyst having both acidic and basic sites gave a maximum glucose conversion of 87% with a 48% yield of HMF at 160 degrees C using 20 wt% catalyst in 12 h. Reusability studies of the catalyst are also presented.

1 aKulkarni, Hemant, S.1 aKamble, Paresh, A.1 aVinod, Chathakudath, P.1 aRathod, Virendra, K.1 aKantam, Mannepalli, Lakshmi uhttps://library.ncl.res.in/content/synthesis-5-hydroxymethylfurfural-glucose-using-tert-butoxyapatite-catalyst01635nas a2200229 4500008004100000022001400041245009500055210006900150260000800219490000700227520086000234653001801094653001201112653001701124653001301141100002801154700002301182700002801205700002101233700003201254856011901286 2025 eng d a1867-388000aSynthesis of glycolic acid from glyoxal by using hydrotalcite catalyst and kinetic studies0 aSynthesis of glycolic acid from glyoxal by using hydrotalcite ca cJUN0 v173 a

In this work, Mg-Al hydrotalcite catalysts with different molar ratios were prepared using the co-precipitation method for the synthesis of glycolic acid (GA) from glyoxal. Various reaction parameters such as catalyst molar ratio, time, temperature, catalyst loading, and catalyst poisoning were studied and optimized for better conversion of glyoxal selectively to glycolic acid. Hydrotalcite catalyst with a 2:1 molar ratio of Mg: Al gives 98% conversion of glyoxal with 96% selectivity of glycolic acid at 100 degrees C temperature, 40% catalyst loading, and water as solvent in 8 h. Different characterization methods were used such as XRD, XPS, SEM-EDX, nitrogen adsorption desorption, and CO2-TPD for hydrotalcite catalyst. A kinetic study was also performed to observe the reaction order and activation energy required for the reaction.

10aGlycolic acid10aGlyoxal10ahydrotalcite10akinetics1 aPandya, Harmitkumar, N.1 aKamble, Paresh, A.1 aVinod, Chathakudath, P.1 aRathod, Virendra1 aKantam, Mannepalli, Lakshmi uhttps://library.ncl.res.in/content/synthesis-glycolic-acid-glyoxal-using-hydrotalcite-catalyst-and-kinetic-studies03320nas a2200289 4500008004100000022001400041245014700055210006900202260000900271300001100280490000800291520230900299100001502608700002302623700001802646700002702664700002602691700001802717700003502735700002302770700001502793700002402808700002802832700001902860700002202879856012902901 2025 eng d a1385-894700aTowards improved activity and stability in RWGS reaction: Dispersed copper in mesoporous alumina matrix as a strategy for enhanced performance0 aTowards improved activity and stability in RWGS reaction Dispers cDEC  a1698630 v5253 a

The development of highly performing Cu-based catalysts with high dispersion of Cu species in nanocrystalline form on a suitable oxide support is significant in reverse water gas shift (RWGS) reaction. We report a simple and robust one-pot sol-gel synthesis of mesoporous Al10-xCuxOy (m gamma-Al10-xCux-SG) catalysts with Cu species in a highly dispersed nanocrystalline form in the gamma-Al2O3 matrix and its high catalytic performance in RWGS reaction. The lack of long range structural order of copper species in m gamma-Al10-xCux-SG catalysts evidenced from Cu-K edge extended X-ray absorption fine structure (EXAFS) studies illustrates the fine distribution of copper species in mesoporous gamma-Al2O3 lattice. Activity study revealed that m gamma-Al10-xCux-SG catalysts showed significantly high CO2 conversion to CO and excellent catalytic stability compared to gamma-Al10-xCux-I prepared by conventional impregnation method. Mesoporous Al9Cu1 (m gamma-Al9Cu1) displayed a CO2 conversion of 45 % at 500 degrees C, which is about 2.8 times higher activity than conventional gamma-Al9Cu1-I catalyst with almost same Cu loading as that of m gamma-Al9Cu1 catalyst. Stability study at 500 degrees C over a period of 50 h revealed that m gamma-Al10-xCux-SG catalysts at low Cu loading (m gamma-Al9.9Cu0.1) showed excellent catalytic stability. The strong copper-alumina interaction in m gamma-Al10-xCux-SG catalysts with enhanced number of active sites at the copper-alumina interface as evidenced from field emission scanning electron microscope (FESEM), high-resolution transmission electron microscope (HRTEM), H2-temperature programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS), electrochemical characterization, and Cu-K edge EXAFS analysis enhances the activity and stability of the catalyst. Density functional theory (DFT) studies and the Operando DRIFTS-MS analysis of RWGS over m gamma-Al9Cu1 catalyst revealed that the mechanism of RWGS reaction to CO formation on m gamma-Al10-xCux-SG catalysts is preceded through the formation of a hydroxycarbonyl (OCOH) intermediate. The present synthesis strategy provides an opportunity for producing Cu-based catalysts with further enhanced activity and stability in RWGS reaction by suitable modification of the catalyst.

1 aSaju, Simi1 aRajendran, Sivaraj1 aOztas, Ulviye1 aRuiz, Sergio, Carrasco1 aReina, Tomas, Ramirez1 aGhosh, Biplab1 aSree, Sreeprasanth, Pulinthana1 aMeena, Raghavendra1 aLi, Guanna1 aBobadilla, Luis, F.1 aVinod, Chathakudath, P.1 aMathew, Thomas1 aShiju, Raveendran uhttps://library.ncl.res.in/content/towards-improved-activity-and-stability-rwgs-reaction-dispersed-copper-mesoporous-alumina02471nas a2200277 4500008004100000022001400041245014400055210006900199260000800268300001200276490000700288520152400295653001001819653001101829653003801840653001701878653002101895653002501916653001101941653002101952653003001973100001702003700002202020700002802042856012302070 2025 eng d a1022-552800aUltra-small Pd nanoparticles on SBA-15: an efficient catalyst for one-pot reductive alkylation of nitrobenzene with size-dependent activity0 aUltrasmall Pd nanoparticles on SBA15 an efficient catalyst for o cFEB a414-4290 v683 a

One-pot reductive alkylation of nitrobenzene with alcohol is an important organic synthesis reaction to form 2 degrees amines. In the present work, we have demonstrated that Pd/SBA-15 can be an effective catalytic system for this reaction. We have designed ultra-small Pd nanoparticles supported on SBA-15 for the synthesis of secondary amine, N-ethylaniline, through one-pot reductive alkylation of nitrobenzene with ethanol under ambient conditions. Ethanol functions both as the alkylating agent and the solvent in this process. The reaction is driven by the simultaneous hydrogenation of nitrobenzene to aniline, dehydrogenation of ethanol to aldehyde, and condensation of aniline and acetaldehyde to form N-ethylaniline. The size of the Pd nanoparticles plays a decisive role in the product selectivity. The undercoordinated sites present on ultra-small Pd NPs can facilitate ethanol dehydrogenation to acetaldehyde, thereby enhancing the selectivity towards N-ethylaniline compared to larger Pd nanoparticles. We have also studied the effect of different mesoporous supports such as SBA-15, MCM-41, and KIT-6 on the N-ethylaniline selectivity and found that SBA-15 was most selective. We have demonstrated that by carefully designing the catalyst such as controlling the Pd NPs size to obtain the maximum quantity of undercoordinated sites and choosing suitable support, the aliphatic alcohols can also be used for reductive alkylation of nitrobenzene in one-pot with optimum yields of N-alkylaniline.

10aKIT-610aMCM-4110aModified deposition precipitation10anitrobenzene10aPd nanoparticles10aReductive alkylation10aSBA-1510asecondary amines10aUndercoordinated Pd sites1 aSoni, Yogita1 aPhilip, Milda, C.1 aVinod, Chathakudath, P. uhttps://library.ncl.res.in/content/ultra-small-pd-nanoparticles-sba-15-efficient-catalyst-one-pot-reductive-alkylation02712nas a2200193 4500008004100000022001400041245006500055210006300120260000900183300001400192490000700206520208600213100002102299700001902320700002802339700002102367700003202388856009802420 2025 eng d a2058-988300aW/HAP catalyzed terpenic alcohols oxidation: kinetic studies0 aWHAP catalyzed terpenic alcohols oxidation kinetic studies cOCT  a2696-27100 v103 a

The selective oxidation of natural alcohols into carbonyl derivatives is a pivotal transformation in synthetic organic chemistry and industrial applications. This study focuses on the oxidation of borneol, a bicyclic secondary terpenic alcohol, into camphor using a tungsten-exchanged hydroxyapatite (W/HAP) catalyst and hydrogen peroxide as a green oxidant. Hydroxyapatite was synthesized via co-precipitation and functionalized with sodium tungstate to create the W/HAP catalyst, which was characterized using techniques such as SEM, EDS, TPD, XPS, and N2 adsorption-desorption to evaluate its surface morphology, porosity, and chemical composition. Oxidation reactions were conducted under optimized conditions, employing dimethylacetamide (DMA) as a solvent to achieve maximum conversion and selectivity. The W/HAP catalyst demonstrated superior performance, achieving nearly 99% conversion of borneol with 100% selectivity for camphor. Reaction parameters, including temperature, reactant stoichiometry, solvent choice, and catalyst loading, were systematically investigated. Higher reaction temperatures and oxidant concentrations favoured rapid conversion while maintaining high selectivity. Solvent effects revealed that DMA stabilized peroxo-tungstate intermediates, enhancing reaction efficiency compared to other solvents. Kinetic studies confirmed a first-order reaction mechanism with respect to borneol, and the activation energy was determined to be 44.23 kJ mol-1, highlighting the catalytic efficiency of W/HAP. Reusability tests confirmed the stability of the W/HAP catalyst over multiple cycles with minimal tungsten leaching. The methodology was extended to other terpenic alcohols, with varying degrees of success, emphasizing the substrate-specific activity of the catalyst. This work underscores the potential of tungsten-based heterogeneous catalysts in sustainable alcohol oxidation and highlights the industrial relevance of camphor synthesis as a renewable and eco-friendly approach to produce fine chemicals, fragrances, and pharmaceuticals.

1 aPoman, Aishwarya1 aKamble, Paresh1 aVinod, Chathakudath, P.1 aRathod, Virendra1 aKantam, Mannepalli, Lakshmi uhttps://library.ncl.res.in/content/whap-catalyzed-terpenic-alcohols-oxidation-kinetic-studies