Electrochemical Synthesis of Hydrogen Peroxide from Carbonate Aqueous Electrolyte by Boron-Doped Diamond Electrode at Industrial-scale Current Densities

Hydrogen peroxide is a widely used oxidant that is involved in many industrial processes, from papermaking to chemical synthesis and wastewater treatment. We report on the electrochemical synthesis of hydrogen peroxide from water oxidation in a carbonate electrolyte by using a boron-doped diamond electrode. The oxidation of carbonate leads to the formation of peroxydicarbonate, and its following hydrolysis produces hydrogen peroxide. We investigated the parameters to maximize the hydrogen peroxide production by optimization of the electrolyte, electrochemical cell configuration, reaction temperature, and applied potential, reaching partial current densities for hydrogen peroxide relevant for possible industrial applications (jH2O2 ≥ 1 A cm–2). In addition, we were able to measure the kinetic constant for the formation of hydrogen peroxide from peroxydicarbonate, which has implications for the reactivity of the electrolyte when used in follow-up reactions. The subtle difference in peroxydicarbonate and hydrogen peroxide production is dictated by the operating temperature.