02177nas a2200193   4500008004100000022001400041245017900055210006900234260000800303300001600311490000600327520141600333100002501749700001801774700002801792700001801820700002401838856012101862       2016                        eng d  a2046-206900aValorization of coffee bean waste: a coffee bean waste derived multifunctional catalyst for photocatalytic hydrogen production and electrocatalytic oxygen reduction reactions0 aValorization of coffee bean waste a coffee bean waste derived mu  cAUG  a82103-821110 v63 a<p>Here, we report the valorization of coffee bean waste (CBW) by producing nitrogen doped porous carbon (p-Cof) having both photocatalytic and electrocatalytic properties using a silica templating method. Morphological investigation of p-Cof reveals the presence of assemblies of highly porous flat carbon blocks. p-Cof exhibits a high surface area (1213 m(2) g(-1)) and a wide range of micro-and mesopores with good electrical conductivity. Along with this, the surface of p-Cof displays the presence of graphitic and pyridone-type nitrogen coordinations, which help p-Cof to perform as a multifunctional catalyst as revealed from its catalytic activities towards photocatalytic hydrogen production (PHP) and electrocatalytic oxygen reduction reactions. p-Cof produces 334 mu mol h(-1) g(-1) of hydrogen from water under visible light and 575 mmol h(-1) g(-1) of hydrogen under solar light irradiation with excellent stability. Along with this, p-Cof also displays improved oxygen reduction reaction (ORR) activity in alkaline medium. A better onset potential (0.91 V vs. RHE) and half-wave potential (0.75 V vs. RHE) are displayed by p-Cof compared to the catalyst derived from the simple annealing of CBW without employing the silica template. Along with the better electrochemical activity, p-Cof shows excellent ORR kinetics and electrochemical stability compared to the current state-of-the-art Pt/C.</p>1 aUnni, SreeKuttan, M.1 aGeorge, Leena1 aBhange, Siddheshwar, N.1 aDevi, Nandini1 aKurungot, Sreekumar  uhttps://library.ncl.res.in/content/valorization-coffee-bean-waste-coffee-bean-waste-derived-multifunctional-catalyst02185nas a2200229   4500008004100000022001400041245014400055210006900199260000800268300001100276490000800287520137900295653002201674653003501696653001301731653001201744100002101756700001801777700001701795700001801812856012501830       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<p>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.</p>
10aCO2 hydrogenation10aIn-situ infra red spectroscopy10aRu/Al2O310aRu/TiO21 aDongapure, Pavan1 aBagchi, Sayan1 aMayadevi, S.1 aDevi, Nandini  uhttps://library.ncl.res.in/content/variations-activity-rutio2-and-rual2o3-catalysts-co2-hydrogenation-investigation-situ