Building highly active hybrid double–atom sites in C2N for enhanced electrocatalytic hydrogen peroxide synthesis

Two–electron (2e-) oxygen reduction reaction (ORR) shows great promise for on–site electrochemical synthesis of hydrogen peroxide (H2O2). However, it is still a great challenge to design efficient electrocatalysts for H2O2 synthesis. To address this issue, the logical design of the active site by controlling the geometric and electronic structures is urgently desired. Therefore, using density functional theory (DFT) computations, two kinds of hybrid double–atom supported on C2N nanosheet ([email protected]2N and [email protected]2N) are screened out and their H2O2 performances are predicted. [email protected]2N exhibits higher activity for H2O2 synthesis with a lower overpotential of 0.12 V than [email protected]2N (0.59 V), Ru3Cu(110) facet (0.60 V), and PdCu(110) facet (0.54 V). In aqueous phase, the adsorbed O2 is further stabilized with bulk H2O and the thermodynamic rate–determining step of 2e- ORR change. The activation barrier on [email protected]2N is 0.43 eV lower than the one on [email protected]2N with 0.68 eV. [email protected]2N is near the top of 2e- ORR volcano plot, and exhibits high selectivity of H2O2. This work provides guidelines for designing highly effective hybrid double–atom electrocatalysts (HDACs) for H2O2 synthesis.