02314nas a2200241 4500008004100000022001400041245011900055210006900174260008900243300001200332490000800344520137100352653002601723653002801749653001901777653001401796653001201810653002501822100003201847700003201879700003001911856013101941 2009 eng d a0169-433200aElectronic decoupling of surface layers from bulk and its influence in oxidation catalysis: a molecular beam study0 aElectronic decoupling of surface layers from bulk and its influe aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbInst Phys; Indian Assoc Cutivat ScicOCT a443-4480 v2563 a

Interactions between oxygen and Pd-surfaces have important implications, especially towards oxidation reactions, and influence of subsurface oxygen to oxidation reactions is the focus of the present study. In our efforts to understand the above aspects, CO oxidation reactions have been carried out with mixed molecular beam (MB), consisting CO and O(2), on Pd(1 1 1) surfaces under a wide variety of conditions (T = 400-900 K, CO: O(2) = 7: 1 to 1: 10). A new aspect of the above reaction observed in the transient kinetics regime is the evidence for oxygen diffusion into Pd subsurface layers, and its significant influence towards CO oxidation at high temperatures (>= 600 K). Interesting information derived from the above studies is the necessity to fill up the subsurface layers with oxygen atoms to a threshold coverage (theta(O-sub)), above which the reactive CO adsorption occurs on the surface and simultaneous CO(2) production begins. There is also a significant time delay (G) observed between the onset of oxygen adsorption and CO adsorption (and CO(2) production). Above studies suggest an electronic decoupling of oxygen covered surface and subsurface layers, which is slightly oxidized, from the metallic bulk, which induces CO adsorption at high temperatures and simultaneous oxidation to CO(2). (C) 2009 Elsevier B.V. All rights reserved.

10aElectronic decoupling10aheterogeneous catalysis10amolecular beam10aOxidation10aPd(111)10aSubsurface diffusion1 aThirunavukkarasu, Kandasamy1 aNagarajan, Sankaranarayanan1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/electronic-decoupling-surface-layers-bulk-and-its-influence-oxidation-catalysis-molecular-001751nas a2200265 4500008004100000022001400041245008800055210006900143260007300212300001200285490000800297520080800305653002201113653002501135653002801160653002201188653002001210653001801230653001401248100002401262700003301286700002201319700003001341856011401371 2013 eng d a0926-860X00aDisordered mesoporous V/TiO2 system for ambient oxidation of sulfides to sulfoxides0 aDisordered mesoporous VTiO2 system for ambient oxidation of sulf aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcFEB a132-1380 v4523 a

High sulfide conversion and predominant sulfoxide yield has been observed with 0.1% vanadium doped disordered mesoporous Ti1-xVxO2 material at ambient and sub ambient temperatures using environmentally green H2O2 oxidant. Ti1-xVxO2 materials were prepared by one-pot solution combustion method in less than 15 min and thoroughly characterized by X-ray diffraction, HRTEM, Raman spectra and other physicochemical techniques. Different sulfides, such as, phenylsulfide, methyl-p-tolylsulfide, ethylsulfide, thioanisole, were converted into the corresponding sulfoxide. Isolated V5+ incorporated in the TiO2 lattice is likely to be the active species for the sulfide oxidation reaction. Catalyst recycling studies indicates the robustness of the catalyst. (c) 2012 Elsevier B.V. All rights reserved.

10aAmbient oxidation10aCombustion synthesis10aheterogeneous catalysis10aHydrogen peroxide10aMesoporous TiO210aSulfoxidation10aSulfoxide1 aNegi, Sanjay, Singh1 aSivaranjani, Kumarsrinivasan1 aSingh, Anand, Pal1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/disordered-mesoporous-vtio2-system-ambient-oxidation-sulfides-sulfoxides-001896nas a2200253 4500008004100000022001400041245008800055210006900143260009200212300001400304490000700318520097300325653001201298653001701310653002801327653003001355653001801385653002201403100002601425700001901451700002601470700003001496856011601526 2013 eng d a1533-488000aFunctional and disordered meso-macroporous gamma-Al2-xMxO3 +/- y (M = Cu and/or Ce)0 aFunctional and disordered mesomacroporous gammaAl2xMxO3 y M Cu a a26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USAbAMER SCIENTIFIC PUBLISHERScAPR a2682-26880 v133 aDisordered meso-macro porous Cu-Ce-Al2O3 nanocomposite (gamma-Al2-xMxO3 +/- y, M = Cu and or Ce) with different compositions has been synthesized. In situ templated sol-gel method has been adopted with simple EDTA ethylenediamine tetra aceticacid and ethylenediamine molecules to prepare gamma-Al2-xMxO3 +/- y, (M = Cu and or Ce). Above meso-macro porous materials were characterized by structural, spectroscopy, microscopy and textural techniques. Detailed characterization indicates that Cu2+ ions are introduced into the ceria and alumina lattice positions. Nano composite nature of the gamma-Al2-xMxO3 +/- y has been confirmed by detailed microscopy investigations. Catalytic activity of the above nanocomposite materials have been screened for environmentally important CO oxidation reaction. 30% Ce-60% Al and 10% Cu containing material shows the best activity among other meso-nnacroporous material with (50%) 100% CO oxidation at (107 degrees C) 145 degrees C.10aAlumina10aCO oxidation10aheterogeneous catalysis10aMeso-Macroporous Material10aNanocomposite10aSol-gel synthesis1 aGnanakumar, Edwin, S.1 aJohn, Jino, C.1 aRaja, Thirumalaiswamy1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/functional-and-disordered-meso-macroporous-gamma-al2-xmxo3-y-m-cu-andor-ce-002539nas a2200277 4500008004100000022001400041245012100055210006900176260007100245300001200316490000600328520150200334653002801836653001001864653002101874653002601895653002701921100002601948700002501974700002101999700003202020700002402052700002602076700003002102856012902132 2013 eng d a2155-543500aMgCl2 center dot 6CH(3)OH: a simple molecular adduct and its influence as a porous support for olefin polymerization0 aMgCl2 center dot 6CH3OH a simple molecular adduct and its influe a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAR a303-3110 v33 a

A single phase molecular adduct, MgCl2 center dot 6CH(3)OH has been synthesized using MgCl2 and the simplest alcohol, methanol. Structural, spectroscopic, and morphological studies have been carried out for a better understanding of the single phase MgCl2 center dot 6CH(3)OH adduct. C-13 CPMAS solid state NMR studies show all six methanol molecules are magnetically equivalent and present in a single environment around the Mg2+ center. Raman spectral analysis of the characteristic peak at 708 cm(-1) substantiates octahedral coordination of six CH3OH molecules around Mg2+. Solid state C-13 NMR measurements, made after heat treatment at different temperatures, have been utilized to understand the variations in CH3OH stoichiometry and coordination around Mg2+ with temperature. A titanated active catalyst, TiCl4 on MgCl2 center dot 6CH(3)OH, has also been synthesized and subjected to detailed characterizations. The active catalyst shows high surface area (102 m(2)/g) and mesoporosity. The titanated catalyst has been screened for ethylene polymerization reactions using different cocatalysts (R3Al; R= -CH3, -CH2CH3, and -CH2CH(CH3)(2)). A total of 7.25 kg of polyethylene per gram of catalyst has been obtained with Me3Al cocatalyst, which is six times higher in activity compared with commercial Me3Al/TiCl4/MgCl2 center dot 6EtOH-supported orted catalystAlthough porosity influences the catalytic activity, other factors also seem to contribute to the total catalytic activity.

10aheterogeneous catalysis10aMgCl210aMolecular adduct10aolefin polymerization10aZiegler-Natta catalyst1 aGnanakumar, Edwin, S.1 aGowda, Ravikumar, R.1 aKunjir, Shrikant1 aAjithkumar, Thalasseril, G.1 aRajamohanan, P., R.1 aChakraborty, Debashis1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/mgcl2-center-dot-6ch3oh-simple-molecular-adduct-and-its-influence-porous-support-olefin-002674nas a2200265 4500008004100000022001400041245011200055210006900167260007700236300001200313490000600325520169700331653002802028653001302056653002502069653001902094653002002113100003302133700002502166700001602191700001502207700002702222700003002249856012902279 2014 eng d a1867-388000aDisordered mesoporous TiO2-xNx+Nano-Au: an electronically integrated nanocomposite for solar H-2 generation0 aDisordered mesoporous TiO2xNxNanoAu an electronically integrated aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcFEB a522-5300 v63 a

We report on H-2 generation by photocatalysis driven by simulated white light by electronically integrated Au nanoparticles with multifunctional, disordered mesoporous TiO2-xNx (Au-NT) nanocomposites. Solar H-2 generation (1.5 mmolh(-1)g(-1)) from aqueous methanol has been demonstrated with Au-NT nanocomposites. The water splitting activity of Au-NT is attributed to the 21.1 ps lifetime of charge carriers observed from fluorescence lifetime measurements, which indicates a high electron-injection efficiency from nano-Au to the conduction band of TiO2, and hence charge separation as well as utilization. This is directly supported by the observation of a high photoluminescence emission intensity with Au-NT that highlights the energy transfer from nano-Au to TiO2. The p-n heterojunction observed between the Au (001) and TiO2 (101) facets helps to-wards the higher charge separation and their utilization. A low mesochannel depth (< 10 nm) associated with disordered mesoporous TiO2-xNx helps the charge carriers to move towards the surface for redox reactions and hence charge utilization. Visible-light absorption, as a result of the surface plasmon resonance of nano-Au, is observed in a broad range between 500 and 750 nm, which helps in harvesting visible-light photons. Finally, electronically integrated nano-Au with TiO2-xNx in Au-NT is evident from Raman and X-ray photoelectron spectroscopy measurements. All of these factors help to achieve a high rate of H-2 production. It is likely that a higher rate of H-2 production than that reported here is feasible by strategically locating Au clusters in porous TiO2 to generate hot spots through electronic integration.

10aheterogeneous catalysis10aHydrogen10amesoporous materials10aphotochemistry10awater splitting1 aSivaranjani, Kumarsrinivasan1 aRajaambal, Sivaraman1 aDas, Tanmay1 aRoy, Kanak1 aBhattacharyya, Somnath1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/disordered-mesoporous-tio2-xnxnano-au-electronically-integrated-nanocomposite-solar-h-2-001608nas a2200217 4500008004100000022001400041245010200055210006900157260007700226300001200303490000600315520081200321653002801133653001301161653001101174653001401185653002201199100001501221700003001236856012401266 2014 eng d a1867-388000aNOx reduction at near ambient temperatures and under lean-burn conditions on modified pd surfaces0 aNOx reduction at near ambient temperatures and under leanburn co aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcFEB a531-5370 v63 a

Palladium surfaces that are modified with O atoms in the subsurface broaden the NO reduction temperature regime up to 325 K with O-2-rich NO+H-2+O-2 compositions. Compared to virgin Pd surfaces, up to 150% higher deNO(x) catalytic activity was observed with modified Pd surfaces at the reaction maximum. Molecular beam instrument and ambient-pressure photoelectron spectroscopy were employed to follow the kinetic and surface changes. These results open up a possibility to realize the cold-start reduction of NOx (deNO(x)). DeNO(x) activity reported in the literature with supported Pd catalysts after a simple calcination in air compares well with our present observations. Surface modification is likely to demonstrate a high potential for other catalytic reactions at relatively low temperatures.

10aheterogeneous catalysis10anitrogen10aoxygen10aPalladium10asurface chemistry1 aRoy, Kanak1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/nox-reduction-near-ambient-temperatures-and-under-lean-burn-conditions-modified-pd-001985nas a2200253 4500008004100000022001400041245010300055210006900158260007700227300001400304490000600318520106600324653002001390653000901410653002801419653001401447653001001461100002601471700002901497700002601526700002601552700003001578856012301608 2014 eng d a1867-388000aRole of nanointerfaces in Cu- and Cu plus Au-based near-ambient-temperature CO oxidation catalysts0 aRole of nanointerfaces in Cu and Cu plus Aubased nearambienttemp aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcNOV a3116-31240 v63 a

Disordered mesoporous Cu-doped ceria-zirconia (Cu0.1Ce0.85Zr0.05O2), and gold deposited (Au/Cu0.1Ce0.85Zr0.05O2) catalysts were synthesized and evaluated for CO oxidation. Onset of CO oxidation activity, and 50% (100%) CO2 formation occurs at room temperature (RT), and 77 (120)degrees C, respectively, with Cu0.1Ce0.85Zr0.05O2. A small amount of gold on Cu0.1Ce0.85Zr0.05O2 induces the sustainable oxidation catalysis around RT. Onset of copper reduction temperature decreases from 110 degrees C on Cu0.1Ce0.85Zr0.05O2 to 48 degrees C with Au/Cu0.1Ce0.85Zr0.05O2, highlighting the direct interaction between Cu and Au through a Cu-Au interface. Au particles with a (00 1) facet deposit on an oxygen-deficient site of (111) facet of CeO2-ZrO2. Any decrease in surface Cu-content with increasing Au-content further supports the Au-Cu-Ce/Zr interface interactions. Nanointerfaces of Au clusters on Cu next to oxygen-deficient sites of CeO2-ZrO2 facilitate all the elementary steps of the CO + O-2 reaction to occur in close proximity at ambient conditions.

10acarbon monoxide10aGold10aheterogeneous catalysis10aOxidation10aredox1 aGnanakumar, Edwin, S.1 aNaik, Jarpla, Madhusudha1 aManikandan, Marimuthu1 aRaja, Thirumalaiswamy1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/role-nanointerfaces-cu-and-cu-plus-au-based-near-ambient-temperature-co-oxidation-001693nas a2200253 4500008004100000022001400041245011000055210006900165260007300234300001200307490000800319520077400327653002801101653001001129653002101139653000801160653001501168653002701183100002101210700003201231700002401263700003001287856012201317 2014 eng d a0926-860X00aStructural investigations of porous MgCl2-2-butanol molecular adduct as support for olefin polymerization0 aStructural investigations of porous MgCl22butanol molecular addu aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN a267-2740 v4693 a

A new heterogeneous Ziegler-Natta (Z-N) catalyst support material, MgCl2 center dot 4(CH3CH(OH)CH2CH3) (Mg2BuOH) has been synthesized. 2-Butanol, a linear, secondary alcohol was chosen for the generation of an active MgCl2 support which results in a Z-N catalyst with TiCl4. Significant feature of this work is the formation of rod shaped molecular adduct with highly porous character. Adduct material is characterized by XRD, TG-DTA, Raman spectroscopy, solid-state NMR and SEM. Activity of the Z-N catalyst supported on Mg2BuOH for ethylene polymerization is comparable with that of commercially available heterogeneous Z-N catalyst. However, there is scope to improve the activity by optimizing textural properties. (C) 2013 Elsevier B.V. All rights reserved.

10aheterogeneous catalysis10aMgCl210aMolecular adduct10aNMR10aPolyolefin10aZiegler-Natta catalyst1 aThushara, K., S.1 aAjithkumar, Thalasseril, G.1 aRajamohanan, P., R.1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/structural-investigations-porous-mgcl2-2-butanol-molecular-adduct-support-olefin-002870nas a2200265 4500008004100000022001400041245014500055210006900200260007100269300001400340490000600354520191100360653001202271653002802283653001302311653001402324653001902338653001702357653001402374653002502388100001502413700001602428700003002444856013002474 2014 eng d a2155-543500aTowards a sustainable and near ambient DeNO(x) under lean burn conditions: a revisit to no reduction on virgin and modified pd(111) surfaces0 aTowards a sustainable and near ambient DeNOx under lean burn con a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUN a1801-18110 v43 a

Catalytic conversion of NO in the presence of H-2 and O-2 has been studied on Pd(111) surfaces, by using a molecular beam instrument with mass spectrometry detection, as a function of temperature and reactants composition. N-2 and H2O are the major products observed, along with NH3 and N2O minor products under all conditions studied. Particular attention has been paid to the influence of O-2 addition toward NO dissociation. Although O-2-rich compositions were found to inhibit the deNO(x) activity of the Pd catalyst, some enhancement in NO reduction to N-2 was also observed up to a certain O-2 content. The reason for this behavior was determined to be the effective consumption of the H-2 in the mixture by the added O-2 and O atoms from NO dissociation. NO was proven to compete favorably against O-2 for the consumption of H-2, especially <= 550 K, to produce N-2 and H2O. Compared with other elementary reaction steps, a slow decay observed with the 2H + 0 -> H2O step under SS beam oscillation conditions demonstrates its contribution to the rate-limiting nature of the overall reaction. Pd(111) surfaces modified with O atoms in the subsurface (Md-Pd(111)) induces steady-state NO reduction at near-ambient temperatures (325 K) and opens up a possibility to achieve room temperature emission control. A 50% increase in the reaction rates was observed at the reaction maximum on Md-Pd(111), as compared with virgin surfaces. Oxygen adsorption is severely limited below 400 K, and effective NO + H-2 reaction occurs on Md-Pd(111) surfaces. Valence band photoemission with a UV light source (He I) under different oxygen pressures with APPES clearly identified the characteristics of the Md-Pd(111) surfaces and PdO. The electron-deficient or cationic nature of Md-Pd(111) surfaces enhances the NO dissociation and inhibits oxygen chemisorption <= 400 K under lean-burn conditions.

10adeNO(x)10aheterogeneous catalysis10aHydrogen10alean burn10amolecular beam10anitric oxide10aPalladium10asurface modification1 aRoy, Kanak1 aJain, Ruchi1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/towards-sustainable-and-near-ambient-denox-under-lean-burn-conditions-revisit-no-reduction01866nas a2200229 4500008004100000022001400041245008200055210006900137260007700206300001200283490000600295520102500301653002801326653001401354653003101368653002201399653002501421100003001446700001501476700003201491856011301523 2015 eng d a1867-388000aCan we shift and/or broaden the catalysis regime towards ambient temperature?0 aCan we shift andor broaden the catalysis regime towards ambient  aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcFEB a588-5940 v73 a

An attempt was made to shift the temperature regime of oxidation catalysis towards ambient temperatures by employing surface modification (SM) as a handle. Systematic SM of Pd(111) was performed by O-atom diffusion into the subsurfaces. Virgin and modified Pd(111) catalysts were evaluated for CO oxidation. Typical CO poisoning observed on virgin surfaces was partially lifted, and ambient CO oxidation was observed on the modified surfaces. CO oxidation was followed by the molecular beam method and near-ambient pressure (NAP) photoelectron spectroscopy under different pressure regimes. UV valence band spectral analysis of the SM and the CO+O-2 reaction on modified Pd(111) surfaces under NAP conditions demonstrated changes in the electronic structures of the surfaces with a change in surface potential by 0.35eV and directly probed CO2 formation under the reaction conditions. Supported metal catalysts may be subjected to SM and evaluated for a shift in the catalysis regime for many different reactions.

10aheterogeneous catalysis10aOxidation10aphotoelectron spectroscopy10asurface chemistry10asurface modification1 aGopinath, Chinnakonda, S.1 aRoy, Kanak1 aNagarajan, Sankaranarayanan uhttps://library.ncl.res.in/content/can-we-shift-andor-broaden-catalysis-regime-towards-ambient-temperature-001374nas a2200253 4500008004100000022001400041245010500055210006900160260007700229300001400306490000700320520041200327653002800739653001900767653002100786653003100807653002700838100001900865700002300884700003000907700002900937700002400966856013000990 2015 eng d a1433-785100aSBA-15-oxynitrides as a solid-base catalyst: effect of nitridation temperature on catalytic activity0 aSBA15oxynitrides as a solidbase catalyst effect of nitridation t aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcMAY a5985-59890 v543 a

Solid bases, such as SBA-15-oxynitrides, have attracted considerable interest for potential applications as catalysts in important industrial processes. Reported herein is that by simply tuning the temperature of nitridation (ammonolysis), the catalytic activity of these solid bases can be enhanced. Solid-state NMR spectroscopy and XPS studies provided the reasoning behind this change in activity.

10aheterogeneous catalysis10aNanostructures10aNMR spectroscopy10aphotoelectron spectroscopy10asolid-state structures1 aSingh, Baljeet1 aMote, Kaustubh, R.1 aGopinath, Chinnakonda, S.1 aMadhu, Perunthiruthy, K.1 aPolshettiwar, Vivek uhttps://library.ncl.res.in/content/sba-15-oxynitrides-solid-base-catalyst-effect-nitridation-temperature-catalytic-activity-002198nas a2200241 4500008004100000022001200041245012300053210006900176260000800245300000700253490000800260520135300268653002501621653001601646653002801662653002001690100002701710700002901737700001601766700001501782700003001797856012901827 2018 eng d a974362600aSubtle interaction between Ag and O 2 : a near ambient pressure UV photoelectron spectroscopy (NAP-UPS) investigations0 aSubtle interaction between Ag and O 2 a near ambient pressure UV cMAR a300 v1303 aThe Ag-O2 interaction, which is at the center-stage of Ag-catalyzed partial oxidation reactions, is studied with NAP-UPS up to 0.2 mbar O2 pressure between 295 and 550 K. Three temperature regimes were identified for distinct Ag-O2 interaction, which are (a) 295–390 K, where mainly dissociative chemisorption of O2 happens, (b) 390–450 K, where diffusion of O-atoms into the sub-surfaces of Ag is prominent, and (c) >450 K, where metastable oxide forms on polycrystalline Ag surfaces. The work function (WF) of Ag changed from 4.95 (≤390 K) to 5.30 eV (390–450 K), and then to 5.7 eV (≥450 K) at 0.1 mbar O2 pressure. Oxygen population in the sub-surfaces imparts crucial modifications to Ag at 390–450 K; it makes the surface to be electron-deficient that relates to the change in the WF of Ag and facilitates the formation of space charge layer on Ag surface. Oxygen adsorbed on such modified Ag-surfaces is electrophilic in nature, and this appears at a higher binding energy in core level XPS than the chemisorbed oxygen on metallic Ag. This is supported by angle-dependent NAP-XPS studies. The subsurface population of oxygen in Ag no longer persists at >410 K when the O2 supply is removed. A high ratio of antibonding/bonding O 2p bands suggests the unique silver-oxygen interaction under the measurement conditions.10aElectronic Structure10aepoxidation10aheterogeneous catalysis10aSurface Science1 aGhosalya, Manoj, Kumar1 aReddy, Kasala, Prabhakar1 aJain, Ruchi1 aRoy, Kanak1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/subtle-interaction-between-ag-and-o-2-near-ambient-pressure-uv-photoelectron-spectroscopy02042nas a2200217 4500008004100000022001400041245012900055210006900184260000900253300001400262490000700276520126400283653002601547653002501573653002801598653001401626653000801640100001601648700003001664856013001694 2020 eng d a1867-388000aElectronic structure evolution of Pd@Co nanocatalysts under oxidation and reduction conditions and preferential CO oxidation0 aElectronic structure evolution of PdCo nanocatalysts under oxida cAUG  a4176-41840 v123 a

Herein, we present the surface electronic structure and morphological evolution under reduction and oxidation conditions for Pd@Co (PC) core-shell nanoparticles with different Pd : Co ratio (PC=2 : 1, 1 : 1 and 1 : 2). Extensive measurements have been made with NAPXPS (near ambient pressure x-ray photoelectron spectroscopy) under oxidising and reducing conditions, and ex-situ HRTEM. It has been demonstrated that PC catalysts are thermally stable towards morphological changes, at least up to 575 K. Nonetheless, it shows a significant surface electronic structure changes under reaction environments, which are highly relevant to heterogeneous catalysis. As expected, high (low) population of metallic (oxidised) Co was observed, while retaining core shell structure under reduction (H(2)and vacuum annealing) environment. Interestingly, the Pd-Co metallic interface helps to overcome the pyrophoric nature of cobalt and stabilised a significant amount of metallic Co at Pd-Co interface even in the presence of 0.1 mbar O(2)up to 575 K. The presence of Pd-Co and Pd-Co@Co(3)O(4)interfaces in reaction environment makes the catalyst dual functional. The proof of concept has been explored in terms of oxidation of CO in the presence of H(2)or O-2.

10aCore-Shell morphology10aElectronic Structure10aheterogeneous catalysis10ainterface10aXPS1 aJain, Ruchi1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/electronic-structure-evolution-pdco-nanocatalysts-under-oxidation-and-reduction-conditions02461nas a2200253 4500008004100000022001400041245017300055210006900228260000900297300001600306490000600322520151900328653002801847653001801875653001401893653001901907653002501926100002101951700002701972700002301999700002502022700003002047856013002077 2021 eng d a2574-096200aAqueous methanol to formaldehyde and hydrogen on Pd/TiO2 by photocatalysis in direct sunlight: structure dependent activity of nano-Pd and atomic Pt-coated counterparts0 aAqueous methanol to formaldehyde and hydrogen on PdTiO2 by photo cNOV  a13347-133600 v43 aIn the present investigation, facet-controlled Pd nanoparticles with nanocube (Pd-NC) and truncated octahedron (Pd-TO) morphologies, and their counterparts with half-a-monolayer of atomic Pt coated (0.5 theta(Pt)-Pd-NC and 0.5 theta(Pt)-Pd-TO) surfaces were prepared. All of them were characterized and evaluated as cocatalyst after supporting them on commercial titania (P25) (Pd-NC/P25, Pd-TO/P25, 0.5 theta(Pt)-Pd-NC/P25, and 0.5 theta(Pt)-Pd-TO/P25) under direct sunlight and/or one sun conditions for the oxidation of methanol to formaldehyde along with solar hydrogen production. Pd-NC/P25 shows higher activity for hydrogen generation compared to Pd-TO/P25; however, activity reversal occurs with the above cocatalysts, but, after Pt-coating with further enhanced activity. The highest conversion of methanol (0.2 mu mol/h.mg) to 100% selective formaldehyde was observed with 0.5 theta(Pt)-Pd-TO/P25, while other catalysts show significantly lower methanol conversion in the following order: 0.5 theta(Pt)-Pd-TO/P25 > 0.5 theta(Pt)-Pd-NC/P25 > Pd-NC/P25 > Pd-TO/P25. Pt-coated on (111) facets of Pd-TO simulates the activity associated as that of Pt(111) facets and demonstrating the highest and facet dependent activity. The present study is truly in resonance with exploiting the surface properties for heterogeneous catalysis, and highlights that less than a monolayer of Pt is sufficient to simulate the activity as that of bulk Pt. It is worth exploring this concept to other metals and substrates too.10aheterogeneous catalysis10aNanomaterials10aOxidation10aPhotocatalysis10asurface modification1 aNalajala, Naresh1 aSalgaonkar, Kranti, N.1 aChauhan, Inderjeet1 aMekala, Siva, Prasad1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/aqueous-methanol-formaldehyde-and-hydrogen-pdtio2-photocatalysis-direct-sunlight-structure01521nas a2200217 4500008004100000245013400041210006900175260000800244300001100252490000700263520073000270653002001000653002001020653001701040653002801057653001701085653001601102100002301118700003001141856013201171 2021 eng d00aCatalytic applications of hydrotalcite and related materials in multi -component reactions: concepts, challenges and future scope0 aCatalytic applications of hydrotalcite and related materials in  cSEP a1004580 v223 aHydrotalcites (HTs) are the potential substitute to conventional base catalysts. HTs are useful in efficient syntheses of various heterocycles, such as chromenes, pyrans, pyrazoles, triazoles, using multi-component reactions. This review focuses on the chemistry of HTs and particularly hydrotalcites and related materials in the synthesis of heterocycles. The effects of preparation method and, physico-chemical parameters, such as calcination, molar ratio of metals, role of intercalated ions, surface area, on the catalytic activities are discussed. Along with technical aspects, this review also unlocks various untouched areas in developing sustainable catalyst for syntheses of heterocycles, drugs, etc. for the future.10agreen chemistry10agreen synthesis10aheterocycles10aheterogeneous catalysis10ahydrotalcite10aMetal Oxide1 aBurange, Anand, S.1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/catalytic-applications-hydrotalcite-and-related-materials-multi-component-reactions-concepts01936nas a2200265 4500008004100000022001400041245013300055210006900188260000800257300001200265490000700277520102200284653002801306653002001334653001901354653001101373653002801384653001901412100002101431700002301452700002101475700001901496700003001515856012501545 2021 eng d a2194-428800aElectronically integrated mesoporous Ag-TiO2 nanocomposite thin films for efficient solar hydrogen production in direct sunlight0 aElectronically integrated mesoporous AgTiO2 nanocomposite thin f cAUG a21003560 v103 a

The synthesis of mesoporous TiO2 by a solution-based assembly process and Ag/TiO2 nanocomposites is provided. The efficacy of Ag/TiO2 nanocomposite as photocatalyst in thin-film form is demonstrated for solar hydrogen generation in sunlight. Integration of Ag with TiO2 dramatically enhanced the H-2 production: with 1 wt% Ag on TiO2 (TiAg-1), the H-2 yield was observed to be 4.59 mmol h(-1) g(-1), which is 2.3 (30) times larger than 0.5 wt% Ag on TiO2. TiAg-1 shows 4.3 times higher activity in film form compared with its powder counterpart. High photocatalytic efficiency is attributed to the surface plasmon resonance effect of Ag, electronic integration of Ag with TiO2, and subsequent valence band broadening, large distribution of Ag nanoparticles and abundant Ag-TiO2 Schottky junctions, and the later minimizes electron-hole recombination. Interparticle mesoporous network increases necking and the high surface area offers easy accessibility of the reactants to a large number of active sites.

10aheterogeneous catalysis10aheterojunctions10aplasmon effect10aSilver10asolar energy conversion10aSolar hydrogen1 aMani, Sunesh, S.1 aRajendran, Sivaraj1 aNalajala, Naresh1 aMathew, Thomas1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/electronically-integrated-mesoporous-ag-tio2-nanocomposite-thin-films-efficient-solar01537nas a2200265 4500008004100000022001400041245010300055210006900158260000800227520062000235653002000855653001700875653002800892653001700920653001800937100002300955700002100978700002700999700002201026700002101048700002001069700002301089700003001112856012901142 2021 eng d a1610-365300aGreen synthesis of xanthene and acridine-based heterocycles of pharmaceutical importance: a review0 aGreen synthesis of xanthene and acridinebased heterocycles of ph cMAR3 a

Xanthene and acridine-based heterocyclic compounds find applications in cancer chemotherapy, biological staining and laser dyes and are known for their antibacterial and anti-tumor properties. Here we review green catalytic routes for the synthesis of 1,8-dioxo-octahydroxanthenes, 1,8-dioxo-decahydroacridines and related heterocyclic molecules with catalysts such as metal oxides, mixed metal oxides, resins, supported organocatalysts, heteropolyacids, carbon-based materials, zeolites, sulfides and ionic liquids. We compare protocols for their catalytic activities, and proposed mechanisms are discussed.

10agreen chemistry10aheterocycles10aheterogeneous catalysis10aMetal oxides10ananocatalysis1 aBurange, Anand, S.1 aGadam, Komal, G.1 aTugaonkar, Prajyot, S.1 aThakur, Seema, D.1 aSoni, Ravish, K.1 aKhan, Rubej, R.1 aTai, Mubashira, S.1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/green-synthesis-xanthene-and-acridine-based-heterocycles-pharmaceutical-importance-review02754nas a2200253 4500008004100000022001400041245014800055210006900203260000800272300001400280490000700294520185500301653002802156653001902184653003102203653000902234653001802243100002302261700001702284700001702301700002602318700003002344856012602374 2022 eng d a2168-048500aSustainable CO2 reduction on in (2)O(3 )with exclusive CO selectivity: catalysis and in situ valence band photoelectron spectral investigations0 aSustainable CO2 reduction on in 2O3 with exclusive CO selectivit cMAR a3521-35310 v103 a

This study demonstrates a sustainable catalytic CO2 conversion to near 100% CO selectivity at ambient pressure on In2O3. Critically, high CO yield could be observed at the cost of undesired methanation, using a lower than stoichiometric amount of hydrogen in the feed; 1:1 and 1:0.67 CO2:H-2 ratios exhibit 98-99.6% CO selectivity with 25-38% CO2 conversion between 773 and 873 K. CO2 and H-2 conversion under steady-state conditions at 773-873 K suggests a 1:1 ratio of adsorbed reactants (with 1:0.67 CO2:H-2 feed) on the catalyst surface, underscoring the presence of an ideal reactant composition for the reverse water-gas shift reaction, while H-2-rich feed compositions show the H-2-dominated surface. Surface electronic structure changes, under near-operating conditions, were explored with near ambient pressure photoelectron spectroscopy (NAPPES), and the interesting findings are as follows: (a) A shift in the valence band to lower binding energy, up to 0.6 eV, was observed because of electron filling at high temperatures. (b) An observation of heterogeneous nature of the catalyst surface under NAPPES measurement conditions is attributed to the generation of active oxygen vacancy (O-v) sites, which in turn changes the work function of In2O3. (c) The above changes are found to be reversible, when the reaction was stopped. Vibrational features of the reactant molecules were observed to be broadened in the active temperature window of the catalyst supporting the heterogeneous character of the catalyst surface because of dynamic O-v generation. By optimizing gas hourly space velocity, CO2:H-2 ratio, and reaction temperature, exclusive CO selectivity is possible with a H-2:CO2 ratio of similar to 0.67, which will avoid the product separation stage altogether, while minimizing the expensive H-2 in the reactant feed.

10aheterogeneous catalysis10aOxygen vacancy10aphotoelectron spectroscopy10aRWGS10aWork function1 aMhamane, Nitin, B.1 aChetry, Sibo1 aRanjan, Ravi1 aRaja, Thirumalaiswamy1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/sustainable-co2-reduction-2o3-exclusive-co-selectivity-catalysis-and-situ-valence-band02553nas a2200265 4500008004100000022001400041245009700055210006900152260000800221300001100229490000800240520168600248653002701934653002801961653000901989653000801998653002002006100001702026700002102043700001602064700002302080700002602103700003002129856012802159 2023 eng d a1385-894700aCo3O4 for sustainable CO2 reduction and possible fine-tuning towards selective CO production0 aCo3O4 for sustainable CO2 reduction and possible finetuning towa cSEP a1444590 v4713 a

Two main challenges involved in heterogeneous catalytic CO2 reduction are: (a) decreasing the consumption of H2 to the minimum required level with possibly the maximum CO2 conversion, and (b) concurrently enhancing the selectivity of the desired CO, at the cost of methane. Towards meeting these two challenges, Co3O4 spinel has been identified as a potential catalyst and it exhibits predominant CO selectivity > 673 K at atmospheric pressure. CO2 conversion begins > 523 K, with 100% CO selectivity observed > 673 K with CO2:H2 = 3:2. Current work shows a sustainable catalytic CO2 conversion to 100% CO selectivity with Co3O4-Nanocube (NC). Critically, CO selectivity and yield is observed to increase at the cost of methane with smaller amount of H2. 1:1 and 3:2 CO2:H2 ratio exhibits 88-100% CO selectivity with 24-32.5% CO2 conversion between 623 and 823 K. Irrespective of the input CO2:H2, ratio of CO2:H2 uptake changes from around 1:3 at 523 K to 1:1-1.5 at 823 K with concurrent production of significant methane to predominant CO, respectively. Surface electronic state changes was explored by near ambient pressure photoelectron spectroscopy, and the results suggests that Co3O4 is the active phase that promotes CO2 reduction selectively to CO. Broadening observed with the vibrational feature of the CO2 molecules at high temperature underscores the heterogeneous character of the catalyst surface, under operating conditions, due to changing electron density. By optimizing the gas hourly space velocity (GHSV), H2-lean CO2:H2 ratio, and the reaction temperature/pressure, 100% CO selectivity could be broadened to a range of operating conditions.

10aCarbon neutral economy10aheterogeneous catalysis10aRWGS10aSDG10aSurface Science1 aRanjan, Ravi1 aTekawadia, Jyoti1 aJain, Ruchi1 aMhamane, Nitin, B.1 aRaja, Thirumalaiswamy1 aGopinath, Chinnakonda, S. uhttps://library.ncl.res.in/content/co3o4-sustainable-co2-reduction-and-possible-fine-tuning-towards-selective-co-production