Gas-phase hydrogenation of maleic anhydride to butyric acid over Cu/TiO 2/γ-Al 2O 3 catalyst promoted by Pd

Abstract

The promoter effect of palladium on the Cu/TiO 2/γ-Al 2O 3 catalyst was investigated for the gas-phase selective hydrogenation of maleic anhydride to butyric acid at atmospheric pressure. The results show that Pd is added rarely into the Cu/TiO 2/γ-Al 2O 3 catalyst for the hydrogenation of maleic anhydride, the higher selectivity to butyric acid can be obtained. In the absence of Pd (or Cu) in the Cu–Pd/TiO 2/γ-Al 2O 3 catalyst, the selectivity to butyric acid (BA) is nearly zero. Using the Cu–Pd/TiO 2/γ-Al 2O 3 (Pd/Cu=3/100 (atom)) catalyst, 56.2% selectivity to BA and 100% conversion of maleic anhydride were obtained at 280 °C.