Axial optimization of biomimetic nanoenzyme catalysts applied to oxygen reduction reactions.

Inspired by the bio-oxygen oxidation/reduction processes of hemoglobin, iron-based transition metal-like enzyme catalysts have been explored as oxygen reduction reaction (ORR) electrocatalysts. We synthesized a chlorine-coordinated monatomic iron material (FeN 4 Cl-SAzyme) via a high temperature pyrolysis method as a catalyst for the ORR. The half-wave potential ( E 1/2 ) was 0.885 V, which exceeded those of Pt/C and the other FeN 4 X-SAzyme (X = F, Br, I) catalysts. Furthermore, through density functional theory (DFT) calculations, we systematically explored the better performance reason of FeN 4 Cl-SAzyme. This work offers a promising approach toward high-performance single atom electrocatalysts.