02514nas a2200301 4500008004100000022001400041245012200055210006900177260000800246300001200254490000700266520151500273653002101788653002401809653001901833653002301852100001801875700001901893700002201912700001601934700001501950700002701965700003301992700001802025700002302043700002502066856012102091 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. uhttp://library.ncl.res.in/content/morphology-tuned-pt3ge-accelerates-water-dissociation-industrial-standard-hydrogen02436nas a2200253 4500008004100000022001400041245012400055210006900179260000800248300001400256490000700270520155500277653001801832653002101850653003001871653002201901653001701923100002201940700001901962700002701981700002802008700002502036856012102061 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. uhttp://library.ncl.res.in/content/potential-and-time-dependent-dynamic-nature-oxide-derived-pdin-nanocatalyst-during02304nas a2200277 4500008004100000022001400041245009400055210006900149260000800218300001600226490000700242520137500249653001401624653003601638653002501674653004401699653001101743100001901754700002901773700002201802700002701824700001601851700001801867700002501885856011601910 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. uhttp://library.ncl.res.in/content/strain-enhanced-phase-transformation-iron-oxide-higher-alcohol-production-co202243nas a2200277 4500008004100000022001400041245013000055210006900185260000800254300001200262490000700274520132700281653001801608653000701626653002101633653001301654100002201667700001501689700002701704700002201731700002101753700002101774700001801795700002501813856012701838 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. uhttp://library.ncl.res.in/content/structure-tailored-surface-oxide-cu-ga-intermetallics-enhances-co2-reduction-selectivity02396nas a2200277 4500008004100000022001400041245017600055210006900231260000800300300001600308490000700324520139600331100002201727700001501749700001701764700002201781700002701803700001601830700002901846700001701875700002101892700002201913700002801935700002501963856013001988 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. uhttp://library.ncl.res.in/content/tuning-hybridization-and-charge-polarization-metal-nanoparticles-dispersed-over-schiff-base02563nas a2200289 4500008004100000022001400041245013800055210006900193260000800262490000700270520158500277653001701862653002401879653001801903653001201921653001901933100001601952700001501968700001601983700001601999700002202015700002702037700002702064700002802091700002502119856012902144 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. uhttp://library.ncl.res.in/content/intrinsic-charge-polarization-bi19s27cl3-nanorods-promotes-selective-c-c-coupling-reaction01803nas a2200205 4500008004100000022001400041245009700055210006900152260000800221300001400229490000700243520108500250100002701335700002501362700002201387700002101409700001801430700002501448856012401473 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. uhttp://library.ncl.res.in/content/metal-deficiency-tailored-18-electron-rule-stabilizes-metal-based-inorganic-compounds