▎ 摘　　要

Molybdenum oxycarbide clusters are novel nanomaterials that exhibit attractive catalytic activity; however, the methods for their production are currently very restrictive. This work represents a new strategy for the creation of near-subnanometer size molybdenum oxycarbide clusters on multilayer graphene. To adsorb Mo-based polyoxometalates of the type [PMo12O40](3-) as a precursor for Mo oxycarbide clusters, the novel tripodal-phenyl cation N,N,N-tri(4-phenylbutyl)-N-methylammonium ([TPBMA](+)) is synthesized. [TPBMA](+) exhibits superior adsorption on multilayer graphene compared to commercially available cations such as tetrabutylammonium ([nBu(4)N](+)) and tetraphenylphosphonium ([PPh4](+)). Using [TPBMA](+) as an anchor, highly dispersed precursor clusters (diameter: 1.0 +/- 0.2 nm) supported on multilayer graphene are obtained, as confirmed by high-resolution scanning transmission electron microscopy. Remarkably, this new material achieves the catalytic reduction of CO2 to selectively produce CO (approximate to 99.9%) via the reverse water-gas-shift reaction, by applying carbothermal hydrogen reduction to generate Mo oxycarbide clusters in situ.