In situ observations of an active MoS<sub>2</sub> model hydrodesulfurization catalyst.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31186420.
- Also identified by DOI 10.1038/s41467-019-10526-0 and PMC identifier 6560102.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The hydrodesulfurization process is one of the cornerstones of the chemical industry, removing harmful sulfur from oil to produce clean hydrocarbons. The reaction is catalyzed by the edges of MoS<sub>2</sub> nanoislands and is operated in hydrogen-oil mixtures at 5-160 bar and 260-380 °C. Until now, it has remained unclear how these harsh conditions affect the structure of the catalyst. Using a special-purpose high-pressure scanning tunneling microscope, we provide direct observations of an active MoS<sub>2</sub> model catalyst under reaction conditions. We show that the active edge sites adapt their sulfur, hydrogen, and hydrocarbon coverages depending on the gas environment. By comparing these observations to density functional theory calculations, we propose that the dominant edge structure during the desulfurization of CH<sub>3</sub>SH contains a mixture of adsorbed sulfur and CH<sub>3</sub>SH.