Boron-Doped Biomass Carbon Nanostructures as Electrocatalysts for the Two-Electron Oxygen Reduction Reaction

Highly active B atom dopants were successfully introduced into a biomass carbon matrix as promising electrocatalysts for the two-electron oxygen reduction reaction (2e – ORR) to synthesize hydrogen peroxide (H 2 O 2 ) by decomposing boron nanosheets with flash Joule heating (FJH) progress. Moreover, the FJH process can greatly improve the graphitization of biomass carbon leading to rapid electron transfer during electrocatalysis. The as-prepared B atom–doped carbon nanomaterial (f-B s -C) showed greatly enhanced 2e – ORR performance with outstanding H 2 O 2 selectivity (91–94%) at 0.25–0.6 V vs reversible hydrogen electrode (RHE) measured via a rotating ring-disk electrode (RRDE) in an alkaline electrolyte, and the Faradaic efficiency was still greater than 80% during 11 h with a mass activity of 798 mmol g catalyst –1 h –1 in an actual three-electrode flow cell setup. The overall catalytic performance is preferable to the majority of reported carbon-based catalysts. Density functional theory showed that the O atom connected with B atoms can induce charge density deficiency on the B site acting as high catalytic sites. This research provides an exploration to fabricate heteroatom dopants to enhance the catalytic capability of biomass-based carbon catalysts.