BEHAVIOR OF HEX-1-ENE OVER BINARY AND TERNARY CU-CE-AL OXIDE CATALYSTS UNDER A HYDROGEN ATMOSPHERE

New copper and cerium mixed oxides supported on alumina of a high surf ace area (prepared by sol-gel method) have been synthesised. Hex-1-ene undergoes both hydrogenation and isomerization reactions over these c atalysts under a hydrogen atmosphere. The role of each element (Cu, Ce , Al) mas studied as well as the effect of their extent. The activitie s and the selectivities (more particularly the cis/trans ratio of hex- 2-ene products) lead us to propose a mechanism via a non-ionic path. T his pathway can be considered as a balance between a sigma-alkyl semi- hydrogenated intermediate, precursor of the hydrogenated product, and a concerted mechanism (SN2') leading meanly to the isomerization.