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 (0 1 0) 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_xO_y 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.

Title

Computational and Theoretical Chemistry

Publisher

Elsevier

Publisher Country

Netherlands

Indexing

Thomson Reuters

Impact Factor

2.0

Publication Type

Both (Printed and Online)

Volume

1211

Year

2022

Pages

10