Regulation of the reaction pathway to design the high sulfur/coke-tolerant Ce-based catalysts for decomposing sulfur-containing VOCs

Coke and sulfur poisoning was a major challenge for the decomposition of methyl mercaptan (CH3SH). Here, we focused on regulating the reaction pathway to solve the problem instead of adjusting the preparation methods of catalyst. In this study, Ce/MCM-41 catalyst exhibited good stability (approximately 100 h) in dealing with coke/sulfur poisoning, which were ascribed to the size induced change in the properties of active centers where the transformation of CeO2 nanoparticles into CeO2 cluster-scale particles altered the active centers from surface reactive oxygen to strong acid sites. Most of the sulfur elements of CH3SH were converted into H2S and CS2 by these strong acid sites, avoiding the excessive accumulation of sulfide/sulfur on the catalyst, as verified by XRD, XPS, and in situ FT-IR analysis. This work reveals the new reaction pathway and deactivation mechanism of Ce-based catalysts, which provides a promising strategy for the development of a high coke/sulfur-tolerance catalyst for eliminating sulfur-containing organic compounds.