02469nas a2200241   4500008004100000022001400041245013900055210006900194260000900263300001600272490000700288520157200295100002101867700002001888700003701908700002601945700002501971700001901996700003202015700001902047700002602066856013502092       2024                        eng d  a1144-054600aNew insights into the composition and catalytic performance of VOx-Ga/γ-Al2O3 for the oxidative dehydrogenation of propane to propene0 aNew insights into the composition and catalytic performance of V  cAUG   a15077-150870 v483 a<p>
	Oxidative dehydrogenation (ODH) of propane is a promising alternative route for propene production. In this work, we developed a series of vanadium and gallium oxides supported on gamma-Al2O3 catalysts by an incipient wetness impregnation method. Among the employed catalysts, the VGA-2 showed superior catalytic activity, and the catalyst was demonstrated for longevity in ODH of propane with a stable activity using a continuous flow fixed bed reactor at 400 degrees C. H-2-TPR and UV-visible spectra showed the presence of highly dispersed monomeric VOx species with tetrahedral coordination geometry, which influences product selectivity. The characterization results also conferred that the redox nature of vanadium (V5+ and V4+) oxide and higher V5+ content on the surface of the VGA-2 catalysts are more favourable for C-H activation. In addition, the pyridine-FTIR and Ga-71 solid-state NMR studies further substantiated the presence of Lewis acid sites and tetrahedrally coordinated Ga3+Ox species that are highly responsible for the ODHP activity, respectively. Furthermore, in situ-DRIFTS studies conferred that the propane adsorption at ambient temperature showed the formation of intermediate propoxide species with the evolution of sigma-bonds and with further increase in the temperature to 325 degrees C; the stretching vibrations of the =C-H and -C-H bonds in the propylene molecule were observed. The spent catalysts were also analyzed by thermogravimetric analysis, where the optimized catalyst (VGA-2) showed the least coke deposition.</p>
1 aKandasamy, Prabu1 aGawali, Sheetal1 aVenugopalan, Aswathy, Thareparam1 aManikandan, Marimuthu1 aMekala, Siva, Prasad1 aShelke, Ankita1 aAjithkumar, Thalasseril, G.1 aBhatte, Kushal1 aRaja, Thirumalaiswamy  uhttps://library.ncl.res.in/content/new-insights-composition-and-catalytic-performance-vox-ga%CE%B3-al2o3-oxidative-dehydrogenation