PNNL

Abstract

Cs+ modified ?-alumina, titania anatase and zirconia in the absence of WS2 are active catalysts for methanol thiolation. Pyridine and CO adsorption via IR show that Cs+ cations induce higher concentrations and strength of base sites. Reaction rates are similar on all three catalysts, indicating that the Cs+ cations are part of the dominating active sites. Methanol thiolation shows similar apparent activation energies, decreasing with Cs+ concentration. Reaction orders close to 0.5 for both reactants suggest that all three metal oxides and their alkali-metal modified counterparts follow the identical base-catalyzed Langmuir-Hinshelwood mechanism. A reaction between the surface alcoholate and the corresponding sulfhydryl groups is hypothesized to be the pathway for reaction. The authors would like to thank SAINT-GOBAIN NorPro for providing the ZrO2 materials, used in this work. RBD would like to thank the Alexander von Humboldt foundation for financial support. J.A.L. was supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences (BES), Division of Chemical Sciences, Geosciences and Biosciences (Transdisciplinary Approaches to Realize Novel Catalytic Pathways to Energy Carriers, FWP 47319).