Characterization of Ni@Pt and Co@Pt overlayer catalysts using adsorption, reactivity descriptors, and X-ray absorption spectroscopy

Ir@Pt bimetallic overlayer catalysts for aqueous phase glycerol hydrodeoxygenation

“…This heat of adsorption was lower than that of the pure platinum and pure iridium. Such a reduction of overlayer catalyst heat of adsorption compared to the pure overlayer metal is consistent with previous H 2 chemisorption studies on Re@Pd, Ni@Pt, and Co@Pt overlayer catalysts using the same synthesis technique [26,27] and computational predictions which proposed that such an overlayer structure could reduce the d-band center energy and hence weaken the adsorption strength of hydrogen [15].…”

“…Previous studies of Ni@Pt and Co@Pt supported on silica-alumina and γ-alumina showed limited Pt overlayer coverages for overlayer catalysts [17,27]. Silica-alumina supported Ni@Pt and Co@Pt showed platinum overlayer coverages of 26% and 6%, respectively.…”

“…Silica-alumina, which has been shown to possess a relatively high amount of both Brønsted and Lewis acid sites [25], is used as the solid acid support for all catalysts to provide necessary acid functionality to catalyze the dehydration/deoxygenation reactions. Ir@Pt overlayer catalysts are synthesized using the directed deposition technique, which has been reported to successfully synthesize Re@Pd, Ni@Pt, and Co@Pt overlayer catalysts [17,26,27]. Multiple platinum depositions (double and triple depositions) are conducted to study the behaviors of increased platinum overlayer coverage.…”

Bimetallic overlayer catalysts with high selectivity and reactivity for furfural hydrogenation

“…Two pure Pt catalysts were synthesized: 5 wt.% Pt sample was used for hydrogen adsorption studies (H 2 chemisorption and ethylene hydrogenation), and 0.5 wt.% Pt was used for furfural hydrogenation reactions so that the number of Pt active sites per gram of catalyst was similar to Ni-and Cu-based catalysts. Ni@Pt and Cu@Pt overlayer catalysts were prepared using the directed deposition technique [9,12]. This technique was adapted from the refilling method developed by Womes et al [13] which was originally used for synthesizing Pt catalysts with controlled Pt particle sizes.…”

“…The ethylene hydrogenation reactivity has been correlated with hydrogen adsorption strength at low hydrogen coverage [9,12,16]. Although it has been proposed that hydrogen could block catalytic active sites in other reactions [7,8], no evidence was observed showing that such an inhibitive effect of strong hydrogen binding is also present in ethylene hydrogenation.…”