Methane conversion into C2 hydrocarbons promoted by N2 over MoP (001) surface: A DFT investigation

Herein, DFT calculations were employed to investigate direct CH4 catalytic conversion over MoP (001) surface. On the surface, CH4 decomposes completely with H2 formation, while C2 hydrocarbon formation is unlikely. Fortunately, N2 introduction would promote direct CH4 conversion into C2 hydrocarbons. N2* prefers to dissociate into two N* on the surface and complete CH4 decomposition is little influenced. While H2 formation is suppressed and a portion of H* adatoms are abstracted by N* resulting in NH3. Two C* intermediates from CH4 decomposition combine into C2* cluster with 1.35eV barrier. The two C of C2* capture H alternatively producing C2H4 and C2H6 finally. The rate-determining step with 1.78eV barrier happens in NH3 formation. Moreover, desorption of products is favorable, and separation of C2 hydrocarbons and NH3 is ease to achieve.