Structure Sensitive Hydrogen Adsorption: Effect of Ag on Ru/SiO2Catalysts

摘要: The dynamics and energetics of hydrogen chemisorption on silica-supported ruthenium ruthenium–silver bimetallic catalysts were studied by1H NMR spectroscopy microcalorimetry. It was observed that the amount adsorbed Ru particles having intermediate low heats adsorption significantly reduced with increasing amounts silver. desorption rate constants, determined from selective excitation experiments, lower Ru–Ag than those at same temperature coverage. apparent sticking coefficients a catalyst 10 at% Ag more times comparable to reported in literature for adsorbing single crystal. Thus silver found greatly affect both Ru/SiO2. However, ensemble electronic effects did not play any role causing these effects. is postulated here influence due its tendency selectively segregate edge, corner, other coordination structures particle surface. Hence, surfaces be structure sensitive.