Density functional theory study on the catalytic dehydrogenation of methane on MoO₃ (0 1 0) surface

Methane conversion offers hydrocarbon building blocks of high market value, which are easier to transport than natural gas. Under non-oxidative conditions, the process can also produce clean hydrogen fuel. In this study, we explored the catalytic dehydrogenation of methane on molybdenum oxide (MoO₃) surface. Periodic density functional theory calculations were performed to study the adsorption of CH₄ on two different supercells of the MoO₃ (010) surface. It was found that CH₄ adsorption was more favorable on a smooth surface constructed of Mo and O network, rather than a surface made with dangling O atoms as thought before. A reaction mechanism for hydrogen formation was then proposed. The first energy barrier for the H-abstraction step was calculated to be 66.4 kJ/mol, which is lower than previously reported values obtained for simple Mo_xOy clusters. The reactions were discussed using the two-state reactivity approach, where different electronic states can play a role in the H-abstraction step. The mechanism also showed the formation of methyl radicals and ethylene, in addition to molecular hydrogen.

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Published in: Computational and Theoretical Chemistry
License: http://creativecommons.org/licenses/by/4.0/
See article on publisher's website: https://dx.doi.org/10.1016/j.comptc.2022.113689