Oxygen and nitrogen co-doped ordered mesoporous carbon materials enhanced the electrochemical selectivity of O2 reduction to H2O2

Abstract

Electrochemical hydrogen peroxide production from two-electron oxygen reduction reaction, a cost-effective, sustainable and reliable method compared with the traditional anthraquinone process, is attracting growing attention. However, it is challenged by the selectivity of electrocatalysts. In this context, nitrogen and oxygen co-doped ordered mesoporous carbon materials have been successfully fabricated. Benefiting from the ordered pore structure, better dispersion behavior and valid doping effect, a high selectivity (~95.00%), good activity and stability toward H2O2 production were achieved. Systematic characterizations like physical adsorption, zeta potential, X-ray photoelectron spectroscopy and density functional theory (DFT) calculation revealed that interactive effects between pyridinic N and functional groups of COOH/COC largely facilitated the desorption of intermediates (*OOH, * represents an unoccupied active site) in turn enhance the selectivity of electrocatalysts toward H2O2 production. Interestingly, H2O2 produced in situ was applied to Electro-Fenton, the formaldehyde mineralization rate was high to about 88.06%. These findings offer a rational chemical design of electrocatalysts toward H2O2 production and pollutant purification.