A DFT study of methane conversion on Mo-terminated Mo2C carbides: Carburization vs C–C coupling

Molybdenum carbides have been believed to catalyze C–C coupling generate aromatics from methane conversion. Herein, a systematic study of activation on the Mo-terminated Mo2C surfaces performed using density functional theory calculations. Our results indicate that ?-Mo2C surface exhibits superior activity toward activation. Carburization through insertion carbon atoms into subsurface interstitial sites reduces reactivity towards activation; and complete carburization in layer makes it behave similarly ?-Mo2C, which has completely carburized layer, ?-MoC Consequently, dimerization CH* adspecies CC occurs more readily, resulting C2H2*, potential precursor produce long chain hydrocarbons or aromatics. This also demonstrates dynamic nature molybdenum under condition activation, is expected play an important role determining selectivity for, e.g., dehydro-aromatization.