▎ 摘　　要

A new composite Mo2C@NC/NrGO, with very small and well-distributed molybdenum carbide (Mo2C) nanoparticles on N-doped graphene, was prepared via carbonization of the tricomponent composite PMo12-PEI/GO comprising phosphomolybdic acid (H3PMo12O40 center dot xH(2)O), polyethyleneimine (PEI), and graphene oxide (GO). The as-prepared Mo2C@NC/NrGO exhibited outstanding oxidative desulfurization (ODS) performance and achieved the ultra-deep desulfurization of liquid fuel under mild conditions, which was attributed to the synergistic effect of extraction and catalytic oxidation. In particular, catalytic oxidation played a dominant role, which originated from the excellent characteristics of Mo2C@NC/NrGO, such as the small size and even distribution of Mo2C on graphene, as well as the improved activation of oxidant by the electronic transfer of N-doped graphene to Mo2C. For oxidative desulfurization (ODS) of 4000 ppm of DBT, Mo2C@NC/NrGO showed the high kinetic constant (> 0.35 min 1), which can make 4000 ppm of DBT removed completely within 10 min. A HO center dot radical mechanism for oxidative desulfurization (ODS) of fuel oils was revealed on the basis of radical experiments and electron paramagnetic resonance (EPR). Moreover, the prepared catalyst presented a good recyclability for six runs with no significant loss of activities. Overall, Mo2C@NC/NrGO could be suggested as a prospective catalyst for ODS.