XAFS reveals the potential of single-atom catalysts: progress, challenges, and future
image: XAFS technology can characterize metal site structures, perform in situ detection in catalytic reactions, and conduct quantitative analysis. When combined with DFT calculations and machine learning, it enables precise analysis of single-atom catalysts, achieving precision catalysis.
Credit: Nano Research, Tsinghua University Press
Single-atom catalysts (SACs) have attracted widespread attention in the field of catalysis due to their unique atomic dispersion characteristics, extremely high atomic utilization efficiency, and excellent catalytic performance. Accurately identifying their microscopic chemical environment is crucial for revealing catalytic mechanisms and promoting the innovative design of high-performance catalysts, especially for the development of machine learning (ML)-driven precision chemistry.
Dr. Yinjuan Chen from Changzhou University published a review article in Nano Research on June 6, 2025.
"In this review article, we outline the fundamental principles of XAFS technology and systematically elaborate on its key applications and significant advantages in characterizing metal sites in SACs and in situ detection of catalytic reactions. Additionally, from the perspective of integrating theoretical calculations with experimental studies, we delve into the importance of using XAFS in conjunction with first-principles calculations and other methods to accurately determine the fine structure of active sites. We also discuss the key challenges faced by XAFS characterization technology and provide an outlook on its future development," said Dr. Yinjuan Chen, the senior author of this article and a researcher in the School of Petrochemical Engineering at Changzhou University.
XAFS is a spectroscopic technique based on the X-ray absorption phenomenon. It consists of two main parts: X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS). Through the XAFS technique, the microscopic chemical environment of a single atom in SACs can be accurately determined, which is extremely important for understanding its catalytic mechanism.
The authors summarize and illustrate the applications of XAFS in SACs research, mainly including the characterization of metal site structures (including oxidation state analysis, exploration of coordination environments, and detection of metal loading), in situ detection of catalytic reactions, and quantitative analysis. "Traditional characterization techniques struggle to precisely observe the microscopic chemical environment of single-atom catalysts, whereas X-ray absorption fine structure can accurately obtain key information. It has significant advantages in SACs research," said Dr. Yinjuan Chen.
Due to the complexity of SACs systems and the limitations of experimental characterization, it is difficult to deeply understand the fine structure of single-atom active sites solely relying on XAFS experimental data. Therefore, combining theoretical methods such as quantum chemical calculations and molecular dynamics simulations with XAFS characterization technology has become an inevitable choice for revealing the essence of the microscopic chemical environment of SACs. Dr. Yinjuan Chen stated: "Theoretical calculations provide a basis for analyzing the microscopic chemical environment, promoting the development of SACs research."
Currently, XAFS characterization faces issues such as the scarcity of standard libraries, complexity of data analysis, limitations of in situ experimental conditions, and discrepancies between theory and experiment. Dr. Yinjuan Chen's team expects to make breakthroughs in improving the precision of XAFS technology, establishing analysis databases, and deeply integrating with machine learning in the future, promoting the development of SACs and assisting research in related fields.
Other contributors include Xiaohui Zhu, Qinglong Zhou and Yafei Li from the Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology and Green Manufacturing Collaborative Innovation Center at Changzhou University in Changzhou, China; Chen Zhu from the Hua LooKeng Honors College at Changzhou University in Changzhou, China; Haoran Xing from the State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures and School of Chemistry and Chemical Engineering at Nanjing University in Nanjing, China; Hai Xiao from the Department of Chemistry at Tsinghua University in Beijing, China; and Hongying Zhuo from the State Key Laboratory of Catalysis and Dalian Institute of Chemical Physics at Chinese Academy of Sciences in Dalian, China.
This work was supported by National Science Foundation of Jiangsu Province (BK20220618), Postgraduate Research & Practice Innovation Program of Jiangsu Province (KYCX24_3199) and AI S&T Program (Grant No. DNL-YL A202209) of Yulin Branch, Dalian National Laboratory for Clean Energy, CAS.
About the Authors
Dr. Yinjuan Chen (陈银娟) is a full lecturer and Master's Supervisor in the school of petrochemical engineering at Changzhou University in China. She has earned PhD in 2021 from China University of Petroleum (East China), specializing in Chemical Engineering and Technology at the State Key Laboratory of Heavy Oil Processing, under the supervision of Professor Chenguang Liu (刘晨光). From October 2016 to July 2021, conducted joint PhD research at the Department of Chemistry, Tsinghua University, focusing on theoretical calculations, structural design, and electronic structure analysis of single-atom catalysis, guided by Professor Jun Li (李隽). Joined the School of Petrochemical Engineering at Changzhou University in July 2021 after completing the PhD. Her research interests focus on the theoretical and computational chemistry, material design and theoretical studies of heterogeneous single-atom catalysts, exploration of mechanisms related to electrochemical energy storage materials and applications of AI in energy storage materials research. Currently, she has published over 20 SCI papers as the first author, co-first author (related to theoretical research in experimental collaboration), or corresponding author in domestic and international journals, including J. Am. Chem. Soc., Angew. Chem. Int. Ed., Nat. Commun., ACS Catal., Chinese J. Catal., Nano Res., J. Energy Chem., Sci. China Mater. She has led one Jiangsu Natural Science Foundation Youth Fund project and participated in another Jiangsu Natural Science Foundation Youth Fund project.
https://che.cczu.edu.cn/2023/0306/c2960a319543/page.htm. https://scholar.google.com/citations?user=PTByO5wAAAAJ&hl=zh-CN
About Nano Research
Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 7,000 articles. In 2024 InCites Journal Citation Reports, its 2024 IF is 9.0 (8.7, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.