Simultaneous Desulfurization and Hydrogenation of Model Diesel Fuel over Ni/ZnO–PdPt/USY Hybrid Catalyst

Abstract

The clean production requires deep desulfurization to meet stringent environmental specification and aromatics hydrogenation to improve the quality of transport fuels. To achieve this objective, hybrid catalyst was prepared by mixing of PdPt/USY with Ni/ZnO powders. It was found that the hybrid showed higher activity and stability to hydrodesulfurization (HDS) of dibenzothiophene (DBT) and hydrogenation of tetralin than Ni/ZnO or PtPd/USY counterparts. PdPt/USY containing catalysts exhibited high trans/cis ration of decalin, this can be attributed to the isomerization on the acid sites of USY and the reduced interaction between olefinic intermediates with PdPt bimetals. The hybrid catalyst also had high hydrogenation ability and stability to bulky aromatics of pyrene with the existence of DBT. The XRD, XPS, and BET characterizations revealed that PdPt/USY is responsible for DBT HDS, HYD and isomerization whereas Ni/ZnO play supporting role as sulfur adsorbent in hybrid catalyst. Hydrogen spillover between Ni/ZnO and PdPt/USY components facilitates the aromatic hydrogenation and DBT HDS. This study proposed that the PdPt/USY–Ni/ZnO hybrid catalyst may be an alternative in the hydrotreatment of diesel fuel.