Catalytic and DRIFTS Studies of Pt-Based Bimetallic Alloy Catalysts in Aqueous-Phase Reforming of Glycerol

PtM (M = Fe, Co, Ni, or Cu)/gamma-Al2O3 catalysts with the same metals size and dispersion are prepared by loading presynthesized PtM colloids on gamma-Al2O3. The effect on catalytic properties over different alloys are investigated by both glycerol aqueous-phase reforming (APR) and water gas shift (WGS) reactions. The Pt1Fe1/gamma-Al2O3 catalyst performs the best activities for both APR and WGS. The relationship between WGS and APR is discussed and suggests that WGS plays a key role in APR Furthermore, DRIFTS study is adopted to understand the possible reaction pathway. Fe plays two roles: (1) the Fe could facilitate the dissociation of H2O to supply the OH group, which is necessary to react with CO adsorbed on Pt; (2) the formation of Pt1Fe1 alloy is beneficial to the decomposition/desorption of formate species that has a tendency to block the active sites. Finally, one possible mechanism of glycerol APR on Pt1Fe1 alloy catalyst is proposed.