02184nas a2200229 4500008004100000022001400041245014400055210006900199260000800268300001100276490000800287520137900295653002201674653003501696653001301731653001201744100002101756700001801777700001701795700001801812856012401830 2020 eng d a2468-823100aVariations in activity of Ru/TiO(2 )and Ru/Al2O3 catalysts for CO2 hydrogenation: an investigation by in-situ infrared spectroscopy studies0 aVariations in activity of RuTiO2 and RuAl2O3 catalysts for CO2 h cFEB a1107000 v4823 a

CO2 hydrogenation to methane, an important reaction strategically and also for value adding to CO2, is investigated on two different catalysts, Ru supported on alumina as well as titania to understand better low temperature activity of Ru/TiO2 catalyst. In-situ infrared studies are carried out in three different steps, viz., (i) CO2 adsorption on fully reduced catalyst (ii) reaction of these adsorbed species with gaseous H-2 and (iii) under co-feed of CO2 and H-2, at different temperatures. On Ru/Al2O3 catalyst, CO2 reacts with hydroxyls on the support surface to form carbonate and adsorbs reductively on metal as CO. Further reduction to formate and methyl species occurs on reaction with H. Small concentration of the reactive intermediate formyl forms only at high temperatures. Whereas, bare TiO2 itself seems capable of reductive adsorption of CO2 as formate indicating enhanced reducibility of titania based catalyst. Formyl groups are observed at low temperatures in Ru/TiO2 in step (ii), which further forms methyl and gaseous methane at much lower temperatures when compared to alumina catalyst. Highly reactive CO species loosely bound to metal-support interface observed at high temperatures, which is not present on Ru/Al2O3 catalyst also makes this catalyst superior. In comparison, linearly bound CO seen in alumina catalyst is not as reactive.

10aCO2 hydrogenation10aIn-situ infra red spectroscopy10aRu/Al2O310aRu/TiO21 aDongapure, Pavan1 aBagchi, Sayan1 aMayadevi, S.1 aDevi, Nandini uhttp://library.ncl.res.in/content/variations-activity-rutio2-and-rual2o3-catalysts-co2-hydrogenation-investigation-situ01941nas a2200229 4500008004100000022001400041245012600055210006900181260000800250300001100258490000800269520113200277653001701409653002301426653002901449653002401478100002201502700002201524700002101546700001801567856012601585 2022 eng d a2468-823100aEffect of B site substitution in Gd2B2-xNiyO7-delta (B= Ti, Zr) ternary metal oxide catalysts in dry reforming of methane0 aEffect of B site substitution in Gd2B2xNiyO7delta B Ti Zr ternar cAPR a1122420 v5223 a

Structured catalysts are emerging as active and durable catalysts in dry reforming of methane due to their inherent characteristics like lattice insertion of active metals and consequent stability imparted. Here we report Ti and Zr substituted Gd2B2-xNiyO7-delta (B = Ti, Zr) catalysts synthesized by citrate gel method, which are characterized and tested for dry reforming of methane. Structure and Ni substitution has been confirmed by Rietveld refinement of powder XRD patterns and Raman analysis. TPR and CO2-TPD were performed to analyze the reducibility and effect of basic sites of catalysts in DRM activity. Ni doped Ti analogue shows stable and superior activity towards dry reforming of methane for 100 h. The in situ IR studies and XPS analysis confirmed the presence of surface hydroxyl species in this catalyst, which triggers the activation of CO2 and provides higher and durable activity in dry reforming reaction. Absence of any C formation in this catalyst after durability test indicates the mechanism of C gasification by the surface hydroxyl species enhancing stable activity for long durations.

10aA(2)B(2)O(7)10aCitrate gel method10aDry reforming of methane10aTernary metal oxide1 aGhodke, Seema, R.1 aThundiyil, Shibin1 aDongapure, Pavan1 aDevi, Nandini uhttp://library.ncl.res.in/content/effect-b-site-substitution-gd2b2-xniyo7-delta-b-ti-zr-ternary-metal-oxide-catalysts-dry01738nas a2200253 4500008004100000022001400041245012800055210006900183260000900252490000700261520089200268653000901160653000801169653001501177653001301192653002601205100002101231700002101252700002201273700001601295700002901311700001801340856012601358 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 uhttp://library.ncl.res.in/content/mechanistic-insights-near-ambient-pressure-activity-intermetallic-nizntio2-catalyst-co2