Modification of Rh/SiO2 catalyst for the hydrogenolysis of glycerol in water

Addition of Re, Mo and W to Rh/SiO2 enhanced the catalytic activity of the glycerol hydrogenolysis using water as a solvent. The modification with Re gave the highest conversion and yield of 1,3-propanediol (1,3-PrD). The optimized Rh-ReOx/SiO2 (Re/Rh = 0.5) catalyst maintained high selectivity to propanediols and suppressed C–C bond breaking even under low H2 pressure and high reaction temperature, where Rh/SiO2 is rather active to C–C bond breaking. Characterization results indicate the formation of ReOx clusters attached to the surface of Rh metal particles. This can cause the synergy between ReOx and Rh, and the glycerol hydrogenolysis proceeds on the interface between Rh metal surface and attached ReOx species.