Hydrogenation of 1,3-pentadiene on modified Pd-containing catalysts

Activity and selectivity of alumina-supported palladium catalysts, particularly the sulfurized ones, in the hydrogenation of 1,3-pentadiene to pentenes were investigated. Preliminary sulfurizing of palladium catalysts considerably enhances the selectivity to olefins in a wide range of the H2 /diene molar ratio (from 2.5 to 10). Samples activated in H2 at elevated temperatures demonstrate a higher activity toward diene hydrogenation. Palladium catalysts are more active at low temperatures of the reaction; however, the earlier studied sulfurized Ni catalysts compare well with palladium ones in terms of their selectivity to olefins and productivity, and are more selective in an excess of hydrogen. Modification of palladium with chromium, silver or lithium increases the selectivity to olefins.