Density Functional Theory Study on Direct Dehydrogenation of Propane Catalyzed by N, O, P Doped Graphene Catalysts

The density functional theory (DFT) was used to calculate the reaction mechanism and selectivity of nonmetallic single-atom catalysts, such as N, O, and P, doped on graphene in the direct dehydrogenation of propane (PDH). Our results show that the rate-controlling step in PDH varies with the doping atom. We also found that N, O, and P nonmetallic single-atom-doped graphene catalysts showed relatively low adsorption performance for propane and the active site was the C atom adjacent to N, O, P, rather than the doped atom itself. Interestingly, for the O-doped graphene catalysts which can reduce the reaction energy barrier by searching for multiple transition states. Finally, the results show that the energy barrier of P-doped propane direct dehydrogenation reflecting the speed control step is the lowest, which is 44.32 kcal·mol−1, and the energy barrier of deep dehydrogenation is 53.08 kcal·mol−1, so it has good selectivity. Therefore, the P-doped graphene catalyst has a promising application as a nonmetallic catalyst for the direct dehydrogenation of propane, which provides the possibility for the design of cheap and environmentally friendly catalysts.