Density functional theory study on direct dehydrogenation of propane catalyzed by N-, O-, and P-doped graphene catalysts

Abstract

The density functional theory 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, and 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, and the more transition states in the reaction path, the lower the energy barrier for the reaction rate-controlling step. 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 PDH, which provides the possibility for the design of cheap and environmentally friendly catalysts.