Atomically dispersed iron on carbon nitride with enhanced oxygen adsorption for efficient and scalable photooxidation.

Su, Zhen; Long, Hua; Song, Siyi; Zhao, Rui-Rui; Zhou, Liang; Gao, Ang; Gao, Ke; Xiao, Wen-Jing · Nat Commun · 2026

basic_science · Level V

Where this comes from

Abstract

Selective oxidation of C-H bonds represents a pivotal transformation for upgrading hydrocarbon feedstocks into value-added chemicals, yet achieving this under mild conditions remains a formidable challenge. We herein disclose a single-atom photocatalytic system featuring nonsymmetric Fe-N<sub>3</sub>Br sites anchored on melem that enables efficient photooxidation of C(sp<sup>3</sup>)-H bonds under mild conditions. The coordination environment facilitates Griffiths-type O<sub>2</sub> adsorption and realizes a high toluene conversion rate of 9.27 × 10<sup>4</sup> μmol g<sup>-1</sup> h<sup>-1</sup>. Experimental and theoretical studies indicate that the Fe-N<sub>3</sub>Br configuration reduces the Fe 3d splitting energy, enhances the O<sub>2</sub> adsorption, and facilitates O<sub>2</sub> activation, thereby promoting superoxide radical (•O<sub>2</sub><sup>-</sup>) generation. The catalyst demonstrates broad functional group tolerance (43 examples, up to 97% yield), and good scalability, enabling a 1000 mmol-scale continuous-flow reaction. This work demonstrates the importance of the single-atom site coordination in governing oxygen activation and provides a scalable, green photocatalytic platform for C-H functionalization.