A comparative study of the electrogeneration of hydrogen peroxide using Vulcan and Printex carbon supports Original Research Article

A comparative study of two different conductive carbon-black pigments, Vulcan XC-72 R and Printex L6, for the electrogeneration of hydrogen peroxide (H2O2) by reducing dissolved oxygen in an alkaline solution was performed. The materials were physically characterized by X-ray diffraction (XRD), Fourier transform infrared attenuated total reflection (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). XRD shows the presence of SO2 and ATR-FTIR technique indicates a difference in NO and SO2 functional groups between the two carbon pigments. XPS indicated presence of SO and NO and more oxygenated acid species on Printex L6. A rotating ring-disk electrode was used for electrochemical analysis of the oxygen reduction reaction (ORR). The results showed that the Printex L6 was better than Vulcan XC-72 R for H2O2 production. Results also indicate that the number of electrons transferred in the ORR for Printex L6 and Vulcan XC-72 R were 2.2 and 2.9, respectively, while the percentages of H2O2 formed were 88% and 51%. Scanning electrochemistry microscopy images confirmed the higher amount of H2O2 formed in the Printex L6 pigment. Printex L6 was shown to be a more promising for H2O2 production than Vulcan XC-72 R, while the latter was shown to have more potential for fuel cells.