Selective Hydrogenation of Maleic Anhydride to Tetrahydrofuran over Cu−Zn−M (M = Al, Ti, Zr) Catalysts Using Ethanol As a Solvent

A series of Cu−Zn−M (M = Al, Ti, Zr) catalysts were prepared by coprecipitation method and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and N2 adsorption. The catalytic activity of the Cu−Zn−M catalyst in maleic anhydride hydrogenation using ethanol as a solvent was studied at 220−280 °C and 1 MPa. The presence of MxOy in Cu−Zn−M (M = Al, Ti, Zr) catalysts favored the deep hydrogenation of maleic anhydride to tetrahydrofuran. The catalysts using TiO2 as a support showed the highest selectivity of tetrahydrofuran. The catalytic activity of the catalysts in the hydrogenation of maleic anhydride to tetrahydrofuran followed a sequence of Cu−Zn−Ti > Cu−Zn−Zr ≈ Cu−Zn−Al.