Process Intensification Approach towards H₂O₂ Electrosynthesis & Electrochemical Advanced Oxidation Processes

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.