02553nas 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-production01739nas a2200253 4500008004100000022001400041245012800055210006900183260000900252490000700261520089200268653000901160653000801169653001501177653001301192653002601205100002101231700002101252700002201273700001601295700002901311700001801340856012701358 2023 eng d a1867-388000aMechanistic insights into near ambient pressure activity of intermetallic NiZn/TiO2 catalyst for CO2 conversion to methanol0 aMechanistic insights into near ambient pressure activity of inte cJAN 0 v153 a

Ni-Zn pair is predicted through descriptor-based studies to be conducive for CO2 hydrogenation. In this study, NiZn (1 : 1) intermetallics supported on TiO2 is identified as a potential candidate for near ambient pressure activity. The effect of reduction temperature on the catalyst textural properties as well as on CO2 to methanol reduction are explored. Structural and microscopic studies provide clear evidence of phase evolution of NiZn alloy with increasing reduction temperatures, along with phase variations of Zn based oxides. Interface between NiZn intermetallics and ZnO nanoparticles observed at reduction temperature of 550 degrees C, seems to play a crucial role in making this system most active and selective to methanol. In addition, in-situ IR studies provide mechanistic insights and indicates the formation of methanolic species even at ambient pressure.

10aCCUS10aCO210aIn-situ IR10aMethanol10anear ambient pressure1 aDongapure, Pavan1 aTekawadia, Jyoti1 aThundiyil, Shibin1 aCaha, Ihsan1 aDeepak, Francis, Leonard1 aDevi, Nandini uhttps://library.ncl.res.in/content/mechanistic-insights-near-ambient-pressure-activity-intermetallic-nizntio2-catalyst-co202193nas a2200181 4500008004100000022001400041245015700055210006900212260000900281300001400290490000700304520149200311100002101803700002101824700001801845700001801863856013001881 2024 eng d a2044-475300aDeciphering the role of chemisorbed CO in CO2 methanation: kinetic and mechanistic investigation over monometallic (Ru) and bimetallic (Ru-Ni) catalysts0 aDeciphering the role of chemisorbed CO in CO2 methanation kineti cDEC  a7124-71330 v143 a

Supported metal catalysts have made prominent contributions to CO2 mitigation through conversion into useful chemicals. However, intermediates and mechanisms involved in this process remain ambiguous. Herein, we present the kinetics, mechanistic route and impact of chemisorbed CO in CO2 methanation on Ru/gamma-Al2O3 and Ru-Ni/gamma-Al2O3 catalysts. Both the catalysts show minimal variation in adsorbed species on changing the duration of reduction, as confirmed through in situ IR spectroscopy. A notable observation is that the adsorbed CO exhibits a red shift at a longer reduction time and a more reactive nature on the Ru/gamma-Al2O3 surface. Conversely, stable bridged CO mode is detected on Ru-Ni/gamma-Al2O3 under similar conditions, leading to catalyst poisoning in all instances. This indicates that pre-reduction duration does not have much effect on the surface but interference of CO has more effect at lower concentrations of reactant gases. In situ XRD analysis reveals limited changes in the metallic or mixed oxide species during these conditions. Reaction kinetic analysis showed that Ru-Ni/gamma-Al2O3 has better rate performance at higher concentrations of CO2, whereas Ru/gamma-Al2O3 exhibits better rate performance at lower concentrations. The activation energy was found to be 74.07 kJ per mole for Ru/gamma-Al2O3 and 89.38 kJ per mole for Ru-Ni/gamma-Al2O3. The turnover frequency (TOF) is directly proportional to the rate of formation of methane.

1 aDongapure, Pavan1 aTekawadia, Jyoti1 aNaidu, Satyam1 aDevi, Nandini uhttps://library.ncl.res.in/content/deciphering-role-chemisorbed-co-co2-methanation-kinetic-and-mechanistic-investigation-over02443nas a2200313 4500008004100000022001400041245012100055210006900176260000800245490000600253520146100259653000801720653001701728653000801745653001501753653000801768653001501776100001801791700002001809700003001829700001701859700002201876700001401898700002201912700002101934700002101955700002401976856012902000 2025 eng d a2366-748600aBinder-free in situ interface reconstruction of NiMoO4 nanorods over Ni(OH)2 nanosheets for efficient urea oxidation0 aBinderfree in situ interface reconstruction of NiMoO4 nanorods o cDEC0 v93 a

Replacing the energy-intensive oxygen evolution reaction (OER) with the urea oxidation reaction (UOR) in electrochemical water splitting offers simultaneous green hydrogen production and urea-rich wastewater oxidation, enhancing energy efficiency and economic viability. In this study, a non-noble metal-based binder-free NiMoO4/Ni(OH)2/NF electrocatalyst is developed, featuring NiMoO4 nanorods anchored on Ni(OH)2 nanosheets. This unique morphology facilitates a highly active in situ reconstructed interface, delivering a current density of 134 mA cm-2 at 1.40 V (vs RHE) in 1 m KOH with 0.33 m urea, significantly outperforming its individual components. The catalyst demonstrates excellent stability over 50 h at 30 mA cm-2. When integrated into an anion exchange membrane urea electrolyser (13 cm2 area) with Pt@C/NF as the HER cathode, the system achieves 192 mA cm-2 at 1.60 V. The post-UOR studies confirm the presence of an amorphous NiMoO4-crystalline Ni(OH)2 interface, which plays a key role in enhancing the availability of the active sites to enhance the UOR performance. The improved electrochemical performance of the engineered catalyst can be ascribed to the in situ reconstructed amorphous-crystalline interface, optimal hydrophilicity, reduced charge transfer resistance, and the distinct morphology. This strategy offers a promising pathway for developing highly active electrocatalysts for energy conversion applications.

10aAEM10aelectrolyser10aOWS10atomography10aUOR10awastewater1 aKumar, Yogesh1 aBarik, Sidharth1 aKharabe, Geeta, Pandurang1 aTorris, Arun1 aSingh, Mayank, U.1 aMohan, S.1 aGalave, Chaitanya1 aTekawadia, Jyoti1 aKanawade, Rajesh1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/binder-free-situ-interface-reconstruction-nimoo4-nanorods-over-nioh2-nanosheets-efficient