Role of initial water content in glycerol hydrogenolysis to 1,2-propanediol over Cu-ZnO catalyst

The work aims to investigate the role of initial water content in the glycerol hydrogenolysis to 1,2-propanediol over Cu-ZnO in depth by characterizing the fresh and spent catalysts in detail with ICP, XRD, XPS, EDS, HRTEM, N-2 sorption, N2O chemisorption, H-2-TPD and NH3-TPD. The glycerol conversion and 1,2-propanediol selectivity gradually reduce simultaneously with increasing initial water content. At higher initial water content, more CuO are formed, bringing about a decrease in the 1,2-propanediol selectivity. The sizes of Cu and ZnO crystallites increase tremendously with increasing initial water content, lowering the active surface area and acidity. Furthermore, the surface Cu content reduces along with the increase of surface Zn content at higher initial water content. The two aspects make a decrease in the glycerol conversion. This work would aid the glycerol hydrogenolysis to 1,2-propanediol over Cu-ZnO with high catalytic efficiency.