Abstract

The effect of Pt and Ru (∼0.6%) added to Mo/Al 2O 3 sulfide catalyst on the simultaneous hydrodesulfurization (HDS) of thiophene and hydrogenation (HYD) of cyclohexene was studied. The addition of Pt and Ru significantly increased the HDS and HYD activities of the Mo/Al 2O 3 catalyst. The addition of Pt led to a weaker synergy in HDS, which was almost independent of the reaction temperature. The addition of Ru led to much stronger synergy in both reactions, which increased at higher reaction temperatures. The synergy in HDS over Ru-promoted catalyst occurred between 240 and 320 °C, approaching values of up to 6. The strong synergy in HYD (up to 4) appeared only at temperatures 300–330 °C and was accompanied by a more than twofold increase in the apparent activation energy. As the most probable explanation, a change in the quality of the sites participating in HYD was proposed. HYD mainly proceeds on separate Ru and Mo sulfides at lower temperatures and while on mixed Ru–Mo–S sites at above 300 °C. This change is ascribed to a partial release of Ru–Mo–S sites by desorption of thiophene or H 2S at the higher temperatures, which compete for the adsorption and reaction with HYD.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.