From Fenton and ORR 2e−-Type Catalysts to Bifunctional Electrodes for Environmental Remediation Using the Electro-Fenton Process

Currently, the presence of emerging contaminants in water sources has raised concerns worldwide due to low rates mineralization, and some cases, zero levels degradation through conventional treatment methods. For these reasons, researchers field are focused on use advanced oxidation processes (AOPs) as a powerful tool for persistent pollutants. These AOPs based mainly in-situ production hydroxyl radicals (OH•) generated from an oxidizing agent (H2O2 or O2) catalyst. Among most studied AOPs, Fenton reaction stands out its operational simplicity good wide range contaminants. However, it limitations such storage handling H2O2. Therefore, electro-Fenton (EF) process been proposed which H2O2 is situ by action oxygen reduction (ORR). important mention that ORR given two routes, four electrons, results products H2O, respectively. this reason, current efforts seek increase selectivity catalysts toward 2e− route thus improve performance EF process. This work reviews reaction, catalysts, presents short review with bifunctional activity processes. Finally, factors dual obtain high catalytic both summarized.