Transfer of molecular oxygen and electrons improved by the regulation of C-N/C = O for highly efficient 2e-ORR

Abstract

In situ hydrogen peroxide (H2O2) production by two-electron oxygen reduction reaction (2e-ORR) is limited by sluggish dynamics which are divided into molecule transfer and reaction kinetics. Ordered matrix and disordered edge is synthesized to regulate molecules and electrons transfer. Interface Atomic Domains (IAD) are used to regulate the dynamics of 2e-ORR, which are a local chemical environment composed of C/N/O atoms (C-N, C = O). IAD are synthesized by biomass tar through pyrolysis, oxidation and doping. Sparse pyridine-N are constructed by the formation of C = O groups and the placeholder of pyrrole-N. Results indicate that surface pyridine-N improves interface electrons transfer, while sparse pyridine-N increases 2e-ORR selectivity. Meanwhile, the surface C = O groups provide strong chemical adsorption for O2 molecules. The collaboration of pyridine-N/C = O groups realized the high activity and selectivity of 2e-ORR. As a result, the synthetic material with N, O-functional groups possesses over 90% selectivity for 2e-ORR during a wide potential range.