Propane hydrogenolysis on bimetallic platinum-cobalt catalysts supported on zeolite beta synthesized with rice husk silica

摘要

Mono- and bimetallic catalysts containing Pt and Co supported on HBEA were prepared by impregnation with Pt loading fixed at 1wt% and Co loading of 5, 10 and 15wt%. The HBEA structure did not change after impregnated with metal but the HBEA crystallinity and surface area decreased with the amount of metal loading. All the catalysts were tested for propane hydrogenolysis which is a structure sensitive reaction. For monometallic catalyst, the 1%Pt/HBEA was the most active catalyst with a nearly complete conversion at 300, 350 and 400 °C but deactivated quickly. The activity and deactivation of Co/HBEA increased with metal loading. The major cause of catalyst deactivation was coking which could be removed by combustion with oxygen. Because 1%Pt/HBEA was the most active catalyst and the 5%Co/HBEA showed the least deactivation, the bimetallic 1%Pt-5%Co/HBEA was investigated further and it gave higher propane conversion and had higher tolerance to deactivation than a physically mixture between 1%Pt/HBEA and 5%Co/HBEA. Thus, a small amount of Co improved the coking tolerance of 1%Pt/HBEA catalyst.