Highly Efficient Electrochemical Production of Hydrogen Peroxide Using the GDE Technology

[Image: see text] This work examines the role of oxygen supply in the improvement of the hydrogen peroxide (H(2)O(2)) electrochemical production efficiency and the generation of high H(2)O(2) concentrations in electrochemical processes operated in a discontinuous mode. To conduct this study, a highly efficient Printex L6 carbon-based gas diffusion electrode (GDE) as a cathode was employed for the electrogeneration of H(2)O(2) in a flow-by reactor and evaluated the effects of lowering the operation temperature (to increase solubility) and increasing the air supply in the system on H(2)O(2) electrogeneration. The results obtained in this study show that unlike what is expected in flow-through reactors, the efficiency in the H(2)O(2) production is not affected by the solubility of oxygen when GDE is employed in the electrochemical process (using the flow-by reactor); i.e., the efficiency of H(2)O(2) production is not significantly dependent on O(2) solubility, temperature, and pressure. The application of the proposed PL6C-based GDE led to the generation of accumulated H(2)O(2) of over 3 g L(–1) at a high current density. It should be noted, however, that the application of the electrocatalyst at lower current densities resulted in higher energy efficiency in terms of H(2)O(2) production. Precisely, a specific production of H(2)O(2) as high as 131 g kWh(–1) was obtained at 25 mA cm(–2); the energy efficiency (in terms of H(2)O(2) production) values obtained in this study based on the application of the proposed GDE in a flow-by reactor at low current densities were found to be within the range of values recorded for H(2)O(2) production techniques that employ flow-through reactors.