Selective ring opening of decalin over bifunctional RuS2/zeolite catalysts

The discovery of sulfur-resistant catalysts for selective ring opening (SRO) is an important challenge for refiners, considering the future legislation on cetane index of diesel fuels. In the present work, we studied the properties of RuS2 supported on several zeolites in gas-phase decalin hydroconversion at high hydrogen pressure (5 MPa) in the presence of 0.8% H2S concentration. Catalytic bifunctionality was investigated by changing the Ru loading or support acidity. The addition of RuS2 strongly improved catalytic activity of an HY zeolite, decreased coke deposition and dehydrogenation and increased selectivity towards RO products. The mechanism mainly proceeds from skeletal isomerization induced by the acidity of the zeolite but the hydrogen activation properties of RuS2 are beneficial to the activity and stability of the catalyst.