Platinum supported on TiO2 as a new selective catalyst on heterogeneous hydrogenation of alpha,beta-unsaturated oxosteroids

Abstract

This paper describes the photochemical deposition of platinum onto TiO2 surface and the full characterization of the catalysts using BET, XPS and TEM techniques. The 1 and 3 wt.% Pt/TiO2 catalysts reveal high activity with 70% and 96% of alpha-diastereoselectivity in the hydrogenation of the carbon-carbon double bond of the alpha,beta-unsaturated oxosteroids 4-androstene-3,17-dione, and 3 beta-acetoxypregna-5,16-dien-20-one, respectively. Using higher temperature and pressure, the catalysts promote the further reduction of C-3 carbonyl group. Catalyst recovering and recycling is easily achieved with no appreciable lost of catalytic activity after five subsequent runs.