Prevention of Catalyst Deactivation in the Hydrogenolysis of Glycerol by Ga₂O₃-Modified Copper/Zinc Oxide Catalysts

Copper/zinc oxide catalysts prepared by coprecipitation were proved to be highly active and selective in the hydrogenolysis of glycerol. However, they suffer from strong deactivation in the course of reaction. Modifying the CuO/ZnO catalyst with Ga2O3 extremely enhances the stability of the catalyst as even after four consecutive experiments over a Cu/ZnO/Ga2O3 catalyst no deactivation is observed. The catalysts were characterized by temperature-programmed reduction, powder X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy coupled with energy-dispersive X-ray analysis, and inductively coupled plasma optical emission spectrometry. As the Cu/ZnO/Ga2O3 catalyst is stable even under harsh reaction conditions of 220 °C and in the presence of water, a space-time-yield as high as 22.1 gpropylene glycol/(gCu h) can be obtained