In Situ Electrochemical Generation of Hydrogen Peroxide in Alkaline Aqueous Solution by using an Unmodified Gas Diffusion Electrode

• Published in: ChemElectroChem Vol. 2; no. 5; pp. 714 - 719
• Main Authors: Barros, Willyam R. P., Ereno, Thaís, Tavares, Ana C., Lanza, Marcos R. V.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY‐VCH Verlag 13.05.2015; John Wiley & Sons, Inc
• Subjects: alkaline medium; Aqueous solutions; Carbon; carbon black; Constants; Diffusion; Electrodes; Energy consumption; Gas diffusion; gas diffusion electrode; Hydrogen peroxide; Low energy; oxygen reduction reaction
• ISSN: 2196-0216; 2196-0216
• DOI: 10.1002/celc.201402426

Hydrogen peroxide (H2O2) is an oxidizing agent commonly used for various applications and is available in aqueous solution in a wide range of concentrations. This work describes the H2O2 electrogeneration process in alkaline medium (KOH 1.0 mol L−1), using an unmodified gas diffusion electrode (GDE) manufactured with Printex 6L carbon. The experiments were performed in a single‐compartment electrochemical cell equipped with a GDE as the working electrode, which was fed with N2 or O2 at a pressure of 0.2 bar. Electrolysis experiments were performed at a constant potential (−0.5≤E≤−1.4 V) for 90 min. The H2O2 concentration reached a maximum value of 3370 mg L−1 at −1.1 V (vs. Ag/AgCl), and H2O2 electrogeneration followed pseudo‐zero‐order kinetics with an apparent rate constant kapp=59.7 mg L−1 min−1. A low energy consumption of 8.0 kWh kg−1 was calculated for these electrogeneration conditions. Volt of confidence: Electrogeneration of H2O2 in alkaline medium, using a gas diffusion electrode with unmodified carbon Printex 6L carbon, exhibits low energy consumption and a high kinetic constant.