Facilitation of Fenton-Like Reaction of Copper-Nitrogen-Doped Carbon-Based Nanocatalysts by Enhancing Hydroxyl Adsorption on Single-Atom Cu-N x C 4- x Sites.

Copper-nitrogen-doped carbon-based nanocatalysts (Cu-NCs), containing atomically dispersed Cu-N x C 4- x sites, are efficient in boosting the Fenton-like reaction. However, the mechanisms of the Fenton-like reaction, including the pH effect on the products and the effect of the coordination environment on catalytic activity, remain controversial, restricting the development of Cu-NCs. Cu-NCs are experimentally synthesized with Cu-N 4 sites and prove that the Fenton-like reaction generates mainly hydroxyl radicals (·OH) in the acidic but ·OH and superoxide radicals (·O 2 - ) in the neutral. The density functional theory (DFT) calculations reveal that the catalytic activity of Cu-NCs in the Fenton-like reaction is associated with the adsorption strength of ·OH at the Cu site. Further investigation of the effect of the coordination environment of Cu-NCs indicates that the Cu-N 2 C 2 site, which can enhance the ·OH adsorption strength, is an ideal catalyst site for the Fenton-like reaction. These results open the way to facilitating the catalytic activity of Cu-NCs in the Fenton-like reaction.