Prof. ZHANG Tao and Prof. WANG Aiqin’s group in Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) reported new Single-Atom Catalysts (SAC).

They fabricated a kind of Fe-N-C SAC, which showed excellent catalytic activity and selectivity for C-H oxidation at room temperature. This work has been published in J. Am. Chem. Soc. (DOI: 10.1021/jacs.7b05130).

M-N-C materials are considered as the promising substitute of noble metal catalysts (e.g., Pt/C) in electrocatalysis and fine chemical synthesis. However, a great discrepancy exists on the nature of the active sites since the catalysts are heterogeneous in both composition and particle size.

In 2016, this group successfully prepared a Co-N-C SAC, which exhibited high activity and selectivity in the hydrogenative coupling of nitroarenes. And they also identified the structure of the active site was CoN₄C₈-1-2O₂ unambiguously (Chem. Sci., 2016, 7, 5758–5764).

Based on previous work, this group recently not only fabricated a highly active Fe-N-C SAC, but also demonstrated the heterogeneity of Fe-N-C SAC although all the iron species were atomically dispersed.

More importantly, it is found that the under-coordinated Fe-N₅, which was only accounted for 18% of all Fe-N_x (x = 4-6) species, stood out to give the best catalytic performance by combining various characterizations and poisoning experiments. This provided a guide to develop more efficient Fe-N-C SAC with more coordination unsaturated Fe-N₅.

This work was supported by the National Natural Science Foundation of China, the Strategic Priority Research Program of the Chinese Academy of Sciences, and the National Key Projects for Fundamental Research and Development of China.

Single-atom dispersed Fe-N-C catalyst with different active sites for C-H bond selective oxidation (Image by LIU Wengang and ZHANG Leilei)