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

Abstract

Abstract Hydrogen peroxide (H 2 O 2 ) 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 H 2 O 2 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 N 2 or O 2 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 H 2 O 2 concentration reached a maximum value of 3370 mg L −1 at −1.1 V (vs. Ag/AgCl), and H 2 O 2 electrogeneration followed pseudo‐zero‐order kinetics with an apparent rate constant k app =59.7 mg L −1 min −1 . A low energy consumption of 8.0 kWh kg −1 was calculated for these electrogeneration conditions.