Hydrogen peroxide electrosynthesis using commercial carbon blacks as catalysts: the influence of surface properties and adsorption performance

BACKGROUND

Surface properties and adsorption performance of carbon materials play a crucial role in the electrochemical two-electron oxygen reduction to produce H₂O₂. However, there is still a lack of in-depth research on commercial carbon blacks in this area. Herein, four typical commercial carbon blacks (Acetylene black (AB), Ketjen black EC 600JD, Vulcan XC 72 and Black Pearls 2000) were used as cathode catalysts to generate H₂O₂. Surface chemistry and pore structure of electrodes of the four carbon blacks were systematically characterized, and their effects on H₂O₂ adsorption, electrochemical generation and degradation were investigated.

RESULTS

Among the four carbon blacks, AB has the highest content of C–O–C/COOH and CO, which are active groups catalyzing the two-electron oxygen reduction reaction to generate H₂O₂. AB has the lowest level of defects and highest degree of graphitization, and AB-modified graphite felt electrode (AB-Ele) has the largest average pore diameter, smallest specific surface area and smaller charge transfer resistance. H₂O₂ production using AB-Ele is the largest and reaches 567.7 mg L⁻¹ at 180 min under a current density of 5 mA cm⁻², and only decreases by 17.6% after 10 repeated uses.

CONCLUSION

Overall, rich oxygen-containing functional groups such as C–O–C, COOH and CO, high degree of graphitization, suitable surface area and porosity as well as weak H₂O₂ adsorption performance are beneficial for the two-electron oxygen reduction reaction to generate H₂O₂. AB-modified graphite felt electrode exhibits good catalytic activity and reusability in H₂O₂ electrosynthesis, demonstrating promising application prospects. © 2024 Society of Chemical Industry (SCI).