Enhanced electrocatalytic performance for H₂O₂ generation by boron-doped porous carbon hollow spheres

Electrocatalytic generation of H₂O₂ via the 2-electron pathway of oxygen reduction reaction (2e-ORR) is an attractive technology compared to the anthraquinone process due to convenience and environmental friendliness. However, catalysts with excellent selectivity and high activity for 2e-ORR are necessary for practical applications. Reported here is a catalyst comprising boron-doped porous carbon hollow spheres (B-PCHSs) prepared using the hard template method coupled with borate transesterification. In an alkali electrolyte, the selectivity of B-PCHS for 2e-ORR above 90% in range of 0.4-0.7 V_RHE and an onset potential of 0.833 V was obtained. Meanwhile, the generation rate of H₂O₂ reached 902.48 mmol h^-1 g_cat^-1 at 0.4 V_RHE under 59.13 mA cm^-2 in batch electrolysis. The excellent catalytic selectivity of B-PCHS for 2e-ORR originates from the boron element, and the catalytic activity of B-PCHS for H₂O₂ generation is contributed to the morphology of porous hollow spheres, which facilitates mass transfer processes.