Mechanisms of direct hydrogen peroxide synthesis on silicon and phosphorus dual-doped graphene: a DFT-D study†
Hydrogen peroxide (H2O2) is an important chemical commodity, with demand growing significantly in chemical synthesis due to its green characteristics. The mechanisms of the direct synthesis of hydrogen peroxide (DSHP) on metal-free silicon and phosphorus dual-doped graphene (Si–P–G) catalyst, based on a dispersion-corrected density functional theory (DFT-D) method, are systematically investigated. The most stable Si–P–G catalyst is presented, with the local region of dopants shown to play an important role in the adsorption and reduction of oxygen. A two-electron pathway is probable for DSHP on Si–P–G according to kinetic and thermodynamic analyses. The hydrogenation of O2 to OOH is the rate-limiting step, with a small barrier energy of 0.66 eV, and the potential energy surface is downhill by Gibbs free energy calculations. All results indicate that Si–P–G is a novel catalyst with high activity and good selectivity for DSHP.