Cocatalytic Fenton Reaction for Pollutant Control

In the field of environmental science, the ideal Fenton reaction is, by definition, Fe2+-catalyzed production of hydroxyl radicals from H2O2. However, in reality, most of the reported Fenton reactions are not real catalytic reactions but redox processes, since when Fe2+ activates H2O2, it becomes Fe3+, and the return to Fe2+ can be difficult. The introduction of a cocatalyst can solve this problem. Here, we review the recent development of typical cocatalytic Fenton strategies for pollutant control, including cocatalysts based on organic acids, zero-valent metals, single atoms, and metal sulfides. The catalytic mechanisms are summarized and cocatalyst regenerations and advantages are examined. It is hoped that our review will enable chemists to develop new catalysts and cocatalysts while focusing on how to use the simplest chemical methods to make the Fenton system work in a stable manner in the long run.