Low-Salt Electrochemical Synthesis of H2O2 Enabled by CO2‑Mediated Radical Chemistry

Abstract Hydrogen peroxide is widely used in daily life, and the on-demand production of bleaching-capable hydrogen peroxide in everyday life environments is a promising approach toward sustainability. Conventional method for producing hydrogen peroxide is the anthraquinone process, which is advantageous for large-scale production but has significant drawbacks, including instability and environmental harm. Therefore, many previous studies have focused on electrochemical hydrogen peroxide production as a replacement for the anthraquinone process, prioritizing the large-scale production to achieve high efficiency. This has led to the predominant use of carbonate solutions exceeding 0.5 M, as higher concentrations are known to improve faradaic efficiency and production rates. However, such conditions are impractical for everyday household use and have resulted in a strong need for low-concentration carbonate systems. Here, we developed a system that enables facile hydrogen peroxide production under household-compatible conditions using a commercial powdered detergent and a soda machine. Notably, in implementing this system, we found that introducing CO2 into a carbonate solution with a low concentration of less than 20 mM significantly enhances hydrogen peroxide production efficiency, enabling the generation of hydrogen peroxide at concentrations up to 6 mM, which is suitable for bleaching applications at home.