Effect of zinc incorporation manner on a Cu–ZnO/Al2O3 glycerol hydrogenation catalyst

A systematic study was undertaken to investigate the effects of zinc incorporation manner on the textural properties, bulk and surface phase compositions, reduction behaviors, and surface acidity of a copper based glycerol hydrogenation catalyst. The catalyst samples were characterized by N2 physisorption, X-ray photoelectron spectroscopy (XPS), X-ray diffraction, transmission electron microscopy, air thermal gravimetric analysis (air-TGA), H2 thermal gravimetric analysis (H2-TGA), and NH3 temperature-programmed desorption. The glycerol hydrogenation performance of the catalysts was studied in a fixed-bed reactor. The characterization results indicated that the zinc promoter incorporated by using the co-precipitation method could improve the dispersion of copper oxide, and decrease the particle size of the copper oxide. The zinc incorporated with the impregnation method is enriched on the catalyst surface. The catalyst prepared by adding zinc using the co-precipitation method provides higher glycerol conversion and 1,2-propanediol selectivity, and lower selectivity to acetol.