Selective hydrogenation of crotonaldehyde on Au supported on mesoporous titania

Abstract

We report here on how gold supported on mesoporous anatase work as a catalyst for the highly-selective hydrogenation of crotonaldehyde into crotyl alcohol. The gold was supported by deposition–precipitation method onto mesoporous titania prepared using hexadecylamine as the structure directing agent. This mesoporous titania provides a narrow pore size distribution and an amorphous framework, which can be converted to another pore size distribution and anatase framework by heating at 673K. Gold was more highly dispersed on mesoporous anatase prepared by heating at 673K than on anatase sample heated at 473–573K or on commercially-available anatase. The structure of these catalysts was analysed by XRD, N2-adsorption/desorption, TEM and XPS. In the hydrogenation of crotonaldehyde at ambient pressure, the selectivity for crotyl alcohol reached 82% on gold supported on mesoporous anatase, while 49% selectivity was obtained for gold supported on commercially-available anatase under the same reaction conditions. In addition, the rate of hydrogenation is also four times greater on Au/mesoporous anatase than on Au/anatase. The selectivity for crotyl aldehyde on gold on mesoporous amorphous titania was 68% under the same reaction conditions.