01949nas 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-methanol01967nas 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-induced02244nas 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-base02271nas 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-electroreduction01876nas 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