Use of Hydrogen Chemisorption and Ethylene Hydrogenation as Predictors for Aqueous Phase Reforming of Lactose over Ni@Pt and Co@Pt Bimetallic Overlayer Catalysts

Abstract

Overlayer Pt on Ni (Ni@Pt) or Co (Co@Pt) were synthesized and tested for H2 generation from APR of lactose. H2 chemisorption descriptor showed that Ni@Pt and Co@Pt overlayer catalysts had reduced H2 adsorption strength compared to a Pt only catalyst, which agree with computational predictions. The overlayer catalysts also demonstrated lower activity for ethylene hydrogenation than the Pt only catalyst, which likely resulted from decreased H2 binding strength decreasing the surface coverage of H2. XAS results showed that overlayer catalysts exhibited higher white line intensity than the Pt catalyst, which indicates a negative d-band shift for the Pt overlayer, further providing evidence for overlayer formation. Lactose APR studies showed that lactose can be used as feedstock to produce H2 and CO under desirable reaction conditions. The Pt active sites of Ni@Pt and Co@Pt overlayer catalysts showed significantly enhanced H2 production selectivity and activity when compared with that of a Pt only catalyst. The single deposition overlayer with the largest d-band shift showed the highest H2 activity. The results suggest that overlayer formation using directed deposition technique could modify the behavior of the surface metal and ultimately modify the APR activity.

Kinetics of Furfural Hydrogenation over Bimetallic Overlayer Catalysts and the Effect of Oxygen Vacancy Concentration on Product Selectivity

“…In this work, two bimetallic overlayer catalysts, Co@Pd and Cu@Pd (core@shell), supported on silica were prepared using the directed deposition technique. Previous studies have demonstrated that supported bimetallic overlayer catalysts synthesized by this technique exhibited the designed overlayer structure and reduced adsorption strength, leading to improved reactivity in hydrogenation or hydrodeoxygenation reactions as anticipated . Catalysts were tested in vapor phase furfural hydrogenation in a fixed‐bed reactor.…”

Hydrogen production from sucrose via aqueous-phase reforming

“…Comparably low selectivity to hydrogen was obtained during the glucose APR over carbon-supported transition metals (Pt, Pt-Ni, Pt-Ru, Pt-Sn, Pt-Ni-Sn) [17]. Lactose APR was investigated over Ni-La/Al2O3, Ni-Co/Al2O3-MgO, and Ni-La/Al2O3 catalysts [18,19] and an overlayer of Pt on Ni or Co on Pt [20].…”