Identifying the active sites in unequal iron-nitrogen single-atom catalysts

Liang Huang; Qiong Liu; Weiwei Wu; Ge Gao; Xiliang Zheng; Jin Wang; Shaojun Dong

doi:10.1038/s41467-023-41311-9

Identifying the active sites in unequal iron-nitrogen single-atom catalysts

Nat Commun. 2023 Sep 11;14(1):5594. doi: 10.1038/s41467-023-41311-9.

Authors

Liang Huang^#^{1

2}, Qiong Liu^#¹, Weiwei Wu^#^{1

2}, Ge Gao¹, Xiliang Zheng¹, Jin Wang^{3

4}, Shaojun Dong^{5

6}

Affiliations

¹ State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China.
² School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, China.
³ Center for Theoretical Interdisciplinary Sciences Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, 325001, China. jin.wang.1@stonybrook.edu.
⁴ Department of Chemistry and Physics, State University of New York at Stony Brook, Stony Brook, NY, 11794-3400, USA. jin.wang.1@stonybrook.edu.
⁵ State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China. dongsj@ciac.ac.cn.
⁶ School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, China. dongsj@ciac.ac.cn.

^# Contributed equally.

Abstract

Single-atom catalysts (SACs) have become one of the most attractive frontier research fields in catalysis and energy conversion. However, due to the atomic heterogeneity of SACs and limitations of ensemble-averaged measurements, the essential active sites responsible for governing specific catalytic properties and mechanisms remain largely concealed. In this study, we develop a quantitative method of single-atom catalysis-fluorescence correlation spectroscopy (SAC-FCS), leveraging the atomic structure-dependent catalysis kinetics and single-turnover resolution of single-molecule fluorescence microscopy. This method enables us to investigate the oxidase-like single-molecule catalysis on unidentical iron-nitrogen (Fe-N) coordinated SACs, quantifying the active sites and their kinetic parameters. The findings reveal the significant differences of single sites from the average behaviors and corroborate the oxidase-like catalytic mechanism of the Fe-N active sites. We anticipate that the method will give essential insights into the rational design and application of SACs.