Supported molybdenum oxide nanoparticles (MoO(x)NPs) have attracted intensive interest due to their unique catalytic properties. Herein, MoO(x)NPs anchored on graphene-analogous boron nitride (g-BN) was prepared by a simple one-step method. The interaction between supports and NPs can be enhanced, and the size of MoO(x)NPs can be controlled during the immobilization process. Molecular oxygen (O-2) in the air can be activated effectively with the as-prepared heterogeneous catalyst. It is noteworthy that experimental results indicate that the controlled MoOxNP size and strong metal oxide support interaction are the two key factors which could help to exhibit high aerobic oxidative desulfurization activity. Moreover, sulfur removal of DBT can still reach 98.0% after recycling 11 times, which indicates that the supported catalyst has a good stability and recycling performance. Finally, the Mo(IV) and Mo(V) parts serve as the active sites to promote the production of superoxide-molybdenum species and the reaction pathway is further proposed.