Density Functional Study On The Adsorption Characteristics Of B And P Doped Graphenes

Based on density functional theory (DFT), the adsorption characteristics of O-. 02> OH and OOH on B-doped-. P-doped and B,P codoped graphenes are studied using first-principle calculations. By analyzing the adsorption energy, bond length, density of states and charge transfer, impacts of the different dopants on the intermediates adsorption of fuel cell oxygen reduction reaction (ORR) are evaluated. The ORR steps are discussed, and the free energy changes of each step are further given. The results show that B, P doped can make graphene significantly enhance the adsorption capacity of each intermediate, and the adsorption energy of various intermediates exhibit similar linear relation. The adsorption energy of P-doped graphene is much larger than B-doped grapheme, while B, P codoped graphene is between them. It’s worth noting that nearest neighbor codoped can make OOH fracture directly, shows stronger adsorption ability. In oxygen reduction reaction, the large adsorption energy of P-doped graphene is beneficial to the fracture reaction of O-O bond in OOH, while the small adsorption energy of B-doped graphene can promote the reaction of OH converting to water. Owing to the synergistic effect, the graphene codoped with B and P has a more balanced adsorption characteristics than B, P single doped graphene, which can more conducive to the adsorption of reactant and desorption of product, then can better catalyze reaction and poses better catalyzing ability than single doped ones.