Kinetic study of 1,5-cyclooctadiene hydro-isomerization on Pd/pumice catalysts

A new route for obtaining 1,4-cyclooctadiene by catalytic isomerization of 1,5-cyclooctadiene at low temperature in presence of H₂ in a three-phase reactor is presented. Wei, Prater and Silvestri methods are used for the kinetic studies. A comparison of the activity-selectivity patterns of the Pd/pumice catalysts with Pd on silica and Pt and Pd–Pt on pumice catalysts is performed. Although Pt catalysts are not active in the hydro-isomerization of 1,5-cyclooctadiene, the presence of small amount of Pt in Pd/pumice catalysts increases the yield to 1,4-cyclooctadiene. Besides the catalyst characteristics, temperature and H₂ pressure influence the production of 1,4-cyclooctadiene. A mechanism of the process is proposed. This revised version was published online in July 2006 with corrections to the Cover Date.