Hydrogenolysis of glycerol over Ni, Cu, Zn, and Zr supported on H-beta

Abstract

A series of transition metal oxides (e.g., Ni, Cu, Zn, and Zr) were supported on H-beta with loading of 5–20wt% via wet impregnation. These catalysts were evaluated in the hydrogenolysis of glycerol under aqueous conditions at different reaction temperatures (150–250°C), times (5–15h) and H2 pressures (300–1200psi). The results from characterization of materials by XRD, FT-IR, N2 sorption and NH3-TPD together with the results from the activity test allowed further understanding of the role of transition metals and acid sites on hydrogenolysis of glycerol. The H-beta was found to contain higher Brønsted acidity and catalyst activity compared to those supported metal catalysts. It was found that the acidic properties of the H-Beta zeolite and metal content play a significant role on the final product distribution. The major product over bare H-beta and Zr/H-beta was 1-proponal, while the concentration of 1,2-propanediol and 1,3-propanediol increased significantly by the incorporation of a second metal oxide. A high 1,3-propanediol selectivity of 14% was obtained over the H-beta supported Ni-Zr catalyst at 73% glycerol conversion. The selectivity of 1,2-propanediol and 1,3-propanediol were decreased at higher reaction temperature and time.