01630nas a2200265 4500008004100000022001400041245013100055210006900186260000800255300001400263490000600277520070900283653002500992653003201017653003001049653001501079653002001094100001901114700001901133700001801152700001801170700002001188700002501208856013101233 2020 eng d a2574-096200aStress-induced electronic structure modulation of manganese-incorporated Ni2P leading to enhanced activity for water splitting0 aStressinduced electronic structure modulation of manganeseincorp cFEB a1271-12780 v33 a

The cornerstone of the emerging hydrogen economy is hydrogen production by water electrolysis with concomitant oxygen generation. Incorporating a third element in metal phosphides can tune the crystalline and electronic structure, hence improving the electrocatalytic properties. In this work, Mn-doped Ni2P with varying ratios of Mn and Ni has been explored as excellent catalysts for water splitting. A complete cell made of the best catalyst Ni1.5Mn0.5P electrodes showed low voltage of 1.75 V at a current density of 10 mA cm(-2) due to enhanced electrical conductivity, induction of tensile stress, enhanced electrochemical surface area, and increased electric dipole upon Mn incorporation.

10aElectronic Structure10ahydrogen evolution reaction10aOxygen Evolution Reaction10aphosphides10awater splitting1 aSarkar, Shreya1 aDheer, Lakshay1 aVinod, C., P.1 aThapa, Ranjit1 aWaghmare, Umesh1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/stress-induced-electronic-structure-modulation-manganese-incorporated-ni2p-leading-enhanced01617nas a2200265 4500008004100000022001400041245010300055210006900158260000800227300001400235490000600249520073700255653001800992653002001010653001501030653000901045653003001054653000901084100002301093700002101116700002201137700003601159700002501195856013101220 2020 eng d a2574-096200aTweaking palladium electronic structure to attain oxygen reduction activity superior to platinum/C0 aTweaking palladium electronic structure to attain oxygen reducti cJUL a6127-61320 v33 a

Enhancing oxygen reduction (ORR) activity through alloying is crucial to improve the performance of a fuel-cell catalysts. In this work, we have studied the alloying effects of 4f rare-earth (RE) metals with palladium. The modified catalyst exhibits better activity (E-onset = 1 V and E-1/2 = 0.88 V) and higher selectivity toward H2O (similar to 97%) compared to the state-of-the-art catalysts due to complete dissociation of O-2. Hirshfeld charge analysis and 2D-electron localization function reveal improved adsorbate-adsorbent interaction on the catalyst surface. This work paves a strategy to design highly selective non-Pt-based catalysts for the ORR by controlling electronic structures and surface oxide formation.

10ad-band center10aDFT calculation10adurability10aEuPd10aoxygen reduction reaction10aYbPd1 aSarma, Saurav, Ch.1 aKaja, Sai, Manoj1 aMishra, Vidyanshu1 aVinod, Chathakudath, Prabhakara1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/tweaking-palladium-electronic-structure-attain-oxygen-reduction-activity-superior-platinumc00688nas a2200169 4500008004100000022001400041245016000055210006900215260000900284300000900293490000700302100001900309700002000328700001800348700002500366856012700391 2021 eng d a1359-734500aConductive interface promoted bifunctional oxygen reduction/evolution activity in an ultra-low precious metal based hybrid catalyst (vol 57, pg 1951, 2021)0 aConductive interface promoted bifunctional oxygen reductionevolu cMAR  a28240 v571 aSarkar, Shreya1 aVarghese, Merin1 aVinod, C., P.1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/conductive-interface-promoted-bifunctional-oxygen-reductionevolution-activity-ultra-low00963nas a2200181 4500008004100000022001400041245013600055210006900191260000800260300001400268490000700282520028100289100001900570700002000589700001800609700002500627856012900652 2021 eng d a1359-734500aConductive interface promoted bifunctional oxygen reduction/evolution activity in an ultra-low precious metal based hybrid catalyst0 aConductive interface promoted bifunctional oxygen reductionevolu cFEB a1951-19540 v573 a

Ultra low PtPd alloy deposited on Ni12P5 nanostructures (PtPd/Ni12P5) exhibited enhanced ORR activity (onset: 1.003 V and E-1/2:0.95 V) on par with commercial Pt/C and superior OER activity with 81% reduction of the precious metal compared to the commercial catalyst.

1 aSarkar, Shreya1 aVarghese, Merin1 aVinod, C., P.1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/conductive-interface-promoted-bifunctional-oxygen-reductionevolution-activity-ultra-low-001949nas 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-methanol01818nas a2200277 4500008004100000022001400041245012800055210006900183260000900252300001400261490000700275520088200282653002001164653002101184653003201205653001801237653002601255100001901281700002001300700001601320700002101336700002301357700001801380700002501398856011701423 2021 eng d a1864-563100aStructure-tailored non-noble metal-based ternary chalcogenide nanocrystals for pt-like electrocatalytic hydrogen production0 aStructuretailored nonnoble metalbased ternary chalcogenide nanoc cAUG  a3074-30830 v143 aA facile microwave-assisted strategy was employed to synthesize Ni3Bi2S2 nanocrystals. Variation in the synthesis conditions tuned the composition of monoclinic and orthorhombic phases of Ni3Bi2S2. The electrochemical hydrogen evolution activity of the catalyst with highest percentage of monoclinic phase demonstrated a negligible onset potential of only 24 mV close to that of state-of-the-art Pt/C with an overpotential as low as 88 mV. Density functional theory calculations predicted the monoclinic phase exhibit the lowest adsorption free energy corresponding to hydrogen adsorption (Delta GadsH*) and, therefore, the highest hydrogen evolution activity amongst the considered phases. The quasi-2D structure of monoclinic phase facilitated an increased charge-transfer between Ni and Bi, favoring the downward shift of the d-band center to enhance the catalytic activity.10acharge transfer10aelectrocatalysis10ahydrogen evolution reaction10aNanomaterials10aternary chalcogenides1 aSarkar, Shreya1 aRawat, Abhishek1 aDas, Tisita1 aGaboardi, Mattia1 aChakraborty, Sudip1 aVinod, C., P.1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/structure-tailored-non-noble-metal-based-ternary-chalcogenide-nanocrystals-pt01879nas a2200289 4500008004100000022001400041245012100055210006900176260000800245300001200253490000700265520093700272653002001209653002101229653001401250653001901264653002101283653002101304100001901325700002001344700001601364700001501380700001801395700002301413700002501436856012801461 2021 eng d a2155-543500aUnveiling the roles of lattice strain and descriptor species on pt-like oxygen reduction activity in Pd-Bi catalysts0 aUnveiling the roles of lattice strain and descriptor species on  cJAN a800-8080 v113 a

A facile non-template-assisted mechanical ball milling technique was employed to generate a PdBi alloy catalyst. The induced lattice strain upon the milling time caused a shift of the d-band center, thereby enhancing the oxygen reduction reaction (ORR) catalytic activity. Additionally, the Pd-O reduction potential and adsorbed OH coverage used as descriptors stipulated the cause of the enhanced ORR activity upon the increased milling interval. Redox properties of surface Pd are directly correlated with a positive shift in the Pd-O reduction potential and OH surface coverage. Hence, by deconvoluting the lattice strain and the role of the descriptor species we achieved a catalyst system with a specific activity 5.4X higher than that of commercial Pt/C, as well as an improved durability. The experimental observation is well-corroborated by a theoretical simulation done by inducing strain to the system externally.

10acharge-transfer10aelectrocatalysis10afuel cell10aLattice strain10aoxygen reduction10aPt-like activity1 aSarkar, Shreya1 aRamarao, S., D.1 aDas, Tisita1 aDas, Risov1 aVinod, C., P.1 aChakraborty, Sudip1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/unveiling-roles-lattice-strain-and-descriptor-species-pt-oxygen-reduction-activity-pd-bi01989nas 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-catalysts02515nas a2200301 4500008004100000022001400041245012200055210006900177260000800246300001200254490000700266520151500273653002101788653002401809653001901833653002301852100001801875700001901893700002201912700001601934700001501950700002701965700003301992700001802025700002302043700002502066856012202091 2022 eng d a0935-964800aMorphology-tuned Pt3Ge accelerates water dissociation to industrial-standard hydrogen production over a wide pH range0 aMorphologytuned Pt3Ge accelerates water dissociation to industri cJUL a22022940 v343 a

The discovery of novel materials for industrial-standard hydrogen production is the present need considering the global energy infrastructure. A novel electrocatalyst, Pt3Ge, which is engineered with a desired crystallographic facet (202), accelerates hydrogen production by water electrolysis, and records industrially desired operational stability compared to the commercial catalyst platinum is introduced. Pt3Ge-(202) exhibits low overpotential of 21.7 mV (24.6 mV for Pt/C) and 92 mV for 10 and 200 mA cm(-2) current density, respectively in 0.5 m H2SO4. It also exhibits remarkable stability of 15 000 accelerated degradation tests cycles (5000 for Pt/C) and exceptional durability of 500 h (@10 mA cm(-2)) in acidic media. Pt3Ge-(202) also displays low overpotential of 96 mV for 10 mA cm(-2) current density in the alkaline medium, rationalizing its hydrogen production ability over a wide pH range required commercial operations. Long-term durability (>75 h in alkaline media) with the industrial level current density (>500 mA cm(-2)) has been demonstrated by utilizing the electrochemical flow reactor. The driving force behind this stupendous performance of Pt3Ge-(202) has been envisaged by mapping the reaction mechanism, active sites, and charge-transfer kinetics via controlled electrochemical experiments, ex situ X-ray photoelectron spectroscopy, in situ infrared spectroscopy, and in situ X-ray absorption spectroscopy further corroborated by first principles calculations.

10aElectrochemistry10ahydrogen production10aintermetallics10awater electrolysis1 aMondal, Soumi1 aSarkar, Shreya1 aBagchi, Debabrata1 aDas, Tisita1 aDas, Risov1 aSingh, Ashutosh, Kumar1 aPrasanna, Ponnappa, Kechanda1 aVinod, C., P.1 aChakraborty, Sudip1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/morphology-tuned-pt3ge-accelerates-water-dissociation-industrial-standard-hydrogen02500nas 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-during02305nas a2200277 4500008004100000022001400041245009400055210006900149260000800218300001600226490000700242520137500249653001401624653003601638653002501674653004401699653001101743100001901754700002901773700002201802700002701824700001601851700001801867700002501885856011701910 2022 eng d a2155-543500aStrain-enhanced phase transformation of iron oxide for higher alcohol production from CO20 aStrainenhanced phase transformation of iron oxide for higher alc cSEP a11118-111280 v123 a

Conversion of CO2 to higher alcohols (HAs) and higher hydrocarbons (HCs) has a greater advantage compared to C1 products because of their high energy density and wide range of applications in daily life. Despite the immense potential of these chemicals, not much of scientific research has been focused on the conversion of CO2 to HAs. In the present work, we have introduced the concept of strain in designing the material to enhance the CO(2 )to HA performance. We introduced strain in a traditional iron-based catalyst, Fe2O3, by the introduction of indium (In), which facilitates the selective conversion of CO2 to HA. An optimum strain favored a 36.7% CO2 conversion with a 42% HA selectivity, and a record yield of 15.42%. The strain has been tuned further with the introduction of K as a promoter. The introduced strain upon In substitution and K promotion favored the conversion of CO2, which is mapped by powder X-ray diffraction, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy. Further, the change in the mechanism upon In incorporation and K promotion has been probed by in situ diffuse reflectance infrared fourier transform spectroscopy, and it is found that the OCHx intermediate, which produces HAs, is more prominent upon In substitution, which favored the enhancement of HA production compared to that of pristine Fe2O3.

10aCO2 to HA10aFischer-Tropsch synthesis (FTS)10aPhase transformation10areverse water gas shift (RWGS) reaction10astrain1 aGoud, Devender1 aChuripard, Sathyapal, R.1 aBagchi, Debabrata1 aSingh, Ashutosh, Kumar1 aRiyaz, Mohd1 aVinod, C., P.1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/strain-enhanced-phase-transformation-iron-oxide-higher-alcohol-production-co202244nas a2200277 4500008004100000022001400041245013000055210006900185260000800254300001200262490000700274520132700281653001801608653000701626653002101633653001301654100002201667700001501689700002701704700002201731700002101753700002101774700001801795700002501813856012801838 2022 eng d a0935-964800aStructure-tailored surface oxide on Cu-Ga intermetallics enhances CO2 reduction selectivity to methanol at ultralow potential0 aStructuretailored surface oxide on CuGa intermetallics enhances  cMAY a21094260 v343 a

Electrochemical CO2 reduction reaction (eCO(2)RR) is performed on two intermetallic compounds formed by copper and gallium metals (CuGa2 and Cu9Ga4). Among them, CuGa2 selectively converts CO2 to methanol with remarkable Faradaic efficiency of 77.26% at an extremely low potential of -0.3 V vs RHE. The high performance of CuGa2 compared to Cu9Ga4 is driven by its unique 2D structure, which retains surface and subsurface oxide species (Ga2O3) even in the reduction atmosphere. The Ga2O3 species is mapped by X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS) techniques and electrochemical measurements. The eCO(2)RR selectivity to methanol are decreased at higher potential due to the lattice expansion caused by the reduction of the Ga2O3, which is probed by in situ XAFS, quasi in situ powder X-ray diffraction, and ex situ XPS measurements. The mechanism of the formation of methanol is visualized by in situ infrared (IR) spectroscopy and the source of the carbon of methanol at the molecular level is confirmed from the isotope-labeling experiments in presence of (CO2)-C-13. Finally, to minimize the mass transport limitations and improve the overall eCO(2)RR performance, a poly(tetrafluoroethylene)-based gas diffusion electrode is used in the flow cell configuration.

10a(2) reduction10aCO10aElectrochemistry10aMethanol1 aBagchi, Debabrata1 aRaj, Jithu1 aSingh, Ashutosh, Kumar1 aCherevotan, Arjun1 aRoy, Soumyabrata1 aManoj, Kaja, Sai1 aVinod, C., P.1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/structure-tailored-surface-oxide-cu-ga-intermetallics-enhances-co2-reduction-selectivity02397nas 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-reaction01804nas a2200205 4500008004100000022001400041245009700055210006900152260000800221300001400229490000700243520108500250100002701335700002501362700002201387700002101409700001801430700002501448856012501473 2023 eng d a0897-475600aMetal deficiency tailored by the 18-electron rule stabilizes metal-based inorganic compounds0 aMetal deficiency tailored by the 18electron rule stabilizes meta cJUL a6050-60580 v353 a

The 18-electron (18-e(-)) rule is typicallyrestrictedto predicting the stability of transition-metal-based complexes. Herein,we report the use of the 18-e(-) to predict the stabilityin a family of intermetallics MNiSn (M = V, Cr, Fe, and Co) crystallizingin the Co1.75Ge structure type. Site deficiencies at theM site obtained from single-crystal X-ray diffraction are understoodas attaining a stable noble gas electronic configuration. The densityfunctional theory -based structure calculation confirms that the deficientstructure is more stable than the ideal occupation available at thecrystal lattice. MnNiSn, which crystallizes in the half-Heusler crystalstructure, depicts the role of covalent radii of the constituent elementsin determining the crystal structure. Using X-ray absorption spectroscopyand X-ray photoelectron spectroscopy, the local structure of the above-mentionedcompounds was also elucidated, supporting the role of deficiency tunedvalence fluctuation to attain a 18-e(-) configurationthat eventually leads to the formation of stable compounds.

1 aSingh, Ashutosh, Kumar1 aMumbaraddi, Dundappa1 aMishra, Vidyanshu1 aRoy, Soumyabrata1 aVinod, C., P.1 aPeter, Sebastian, C. uhttps://library.ncl.res.in/content/metal-deficiency-tailored-18-electron-rule-stabilizes-metal-based-inorganic-compounds01871nas 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-high02271nas 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-coupling02307nas a2200337 4500008004100000022001400041245015300055210006900208260000900277300001100286490000800297520117300305653002001478653002401498653002201522653000901544653002301553653001201576653002501588653004301613100002401656700001801680700001901698700002001717700002501737700001701762700001801779700002501797700001801822856012901840 2025 eng d a1385-894700aExploring the electronic modulation in controlling the activity and selectivity of Ni-Au-In based catalyst in atmospheric pressure CO2 hydrogenation0 aExploring the electronic modulation in controlling the activity  cSEP  a1659210 v5203 a

Nickel-based catalysts are widely used for the hydrogenation of CO2 but encounter stability challenges during prolonged reactions and at elevated temperatures. At atmospheric pressure, nickel primarily promotes methane formation in CO2 hydrogenation reactions. In this work, we demonstrate that the stability and activity of nickel can be significantly enhanced through gold (Au) modification. Furthermore, we achieve a near-complete selectivity switch from methane to CO by incorporating indium (In), mediated through the formation of Au-In alloy. This catalyst exhibits excellent CO2 conversion and CO selectivity at relatively lower temperatures (400 degrees C), addressing a major bottleneck in the Reverse Water-Gas Shifts (RWGS) reaction. XPS studies demonstrate an interesting electron transfer mechanism facilitated by gold, which involves the formation of electronrich Au species (Au delta-) and the development of Au-In alloys. This process improves the reducibility of nickel oxide while allowing a fraction of nickel to remain in its metallic form, managing a facile hydrogenation process and regulating the shift in selectivity from CH4 to CO.

10aAlloy formation10aBimetallic catalyst10aCO2 hydrogenation10aRWGS10aSelectivity switch10asynergy10aTrimetallic catalyst10aXPS (X-ray photoelectron spectroscopy)1 aBajpai, Jyotsna, P.1 aGupta, Sharad1 aGoud, Devender1 aDeka, Diku, Raj1 aJagtap, Anuradha, V.1 aKumar, Pawan1 aAhamed, Momin1 aPeter, Sebastian, C.1 aVinod, C., P. uhttps://library.ncl.res.in/content/exploring-electronic-modulation-controlling-activity-and-selectivity-ni-au-based-catalyst01876nas 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-selective