In situ electrosynthesis of hydrogen peroxide with an improved gas diffusion cathode by rolling carbon black and PTFE

Abstract

A simply structured gas diffusion electrode (GDE) was constructed by rolling carbon black and PTFE as a conductive catalyst layer to enhance the producibility of hydrogen peroxide. A Box–Behnken design (BBD) coupled with response surface methodology was employed to assess the individual and interactive effects of the three main independent parameters (pH, current density and air flow rate) on the H₂O₂ concentration. Analysis of variance (ANOVA) showed a high coefficient of determination value. Optimal operating conditions were a pH value of 4.0, current density of 52 mA cm⁻², and an air flow rate of 55 mL min⁻¹. The predicted H₂O₂ concentration under the optimal conditions determined by the proposed model was 309.85 mM, demonstrating the improved GDE without using noble metals and other chemical promoters is a potential method for in situ electrosynthesis of H₂O₂. Results also revealed that the current density, air flow rate, and their interaction effect had a significant effect on the H₂O₂ concentration, whereas changes to the initial pH had no apparent effect. Experiments showed that current density has a direct effect on the decomposition reaction in the electrolytic process.