Hydrogenation of 1,3-Pentadiene on Modified Pd-Containing Catalysts

The activity and selectivity of sulfidized and non- sulfidized palladium alumina supported catalysts in the hydrogenation of 1,3-pentadiene to pentenes is studied. Preliminary sulfidation of palladium catalysts substantially improves their selectivity toward olefins in a broad range of Н₂ : diene ratios (from 2.5 to 10). Samples activated in Н₂ at elevated temperatures display higher activity in diene hydrogenation. Palladium catalysts are more active at low temperatures of the reaction, but sulfidized Ni catalysts studied earlier are competitive with palladium ones in selectivity toward olefins and productivity, and are more selective in an excess of hydrogen. The modification of palladium with chromium, silver, or lithium improves the selectivity toward olefin.