Process Intensification Approach towards H2O2 Electrosynthesis & Electrochemical Advanced Oxidation Processes

Abstract

The two-electron route oxygen reduction reaction brings new development opportunities for electrochemical advanced oxidation processes but greatly lacks practical engineering attempts and devices. The reaction conditions (e.g., anion, cation, temperature, pH, and organics) play crucial roles in H₂O₂ electrogeneration, which can affect mass transfer and H₂O₂ decomposition. For instance, organics lead to decreases in electrode current and H₂O₂ production, especially in macromolecular matters. The cathode reaction seems to be changed from the O₂ → H₂O₂ route to the O₂ → •OH route, influenced by the metal ions. Particle electrodes, electrode assembly, and bubble-induced convection are applied together to overcome the mass transfer limitations and underutilization of the electroactive area here. A process intensification electrode assembly reactor is proposed, which consists of a PbO₂ anode and an insert H₂O₂ electrogenerated particle cathode. The results of modeling and wastewater tests suggest that the carbon particle cathode and notable turbulent disturbance result in notable enhancements in mass transfer and space-time yield.