| abstract |
A catalyst for the selective hydrogenation of highly unsaturated hydrocarbons, e.g. acetylene, in the presence of less unsaturated hydrocarbons, e.g. ethylene, comprises palladium supported on a calcined refractory material comprising a calcium aluminate cement having a Ca:Al ratio of 1:4 to 1:10, the average depth of penetration of the palladium into the catalyst pieces being less than 300 mu m. |