CO Cryo‐Sorption as a Surface‐Sensitive Spectroscopic Probe of the Active Site Density of Single‐Atom Catalysts
Quantifying the number of active sites is a crucial aspect in the performance evaluation of single metal-atom electrocatalysts. A possible realization is using adsorbing gas molecules that selectively bind to the single-atom transition metal and then probing their surface density using spectroscopic tools. Herein, using in situ X-ray photoelectron spectroscopy (XPS) and near edge X-ray absorption fine structure (NEXAFS) spectroscopy, we detect adsorbed CO gas molecules on a FeNC oxygen reduction single atom catalyst. Correlating XPS and NEXAFS, we develop a simple surface- and chemically-sensitive protocol to accurately and quickly quantify the active site density. Density functional theory-based X-ray spectra simulations reaffirm the assignment of the spectroscopic fingerprints of the CO molecules adsorbed at Fe-N<sub>4</sub>-C sites, and provide additional unexpected structural insights about the active site needed to explain the low-temperature CO adsorption. Our work represents an important step towards an accurate quantitative catalytic performance evaluation, and thus towards developing reliable material design principles and catalysts.
Authors
- Geunsu Bae (ORCID: https://orcid.org/0000-0002-6714-1647)
- Frédéric Jaouen (ORCID: https://orcid.org/0000-0001-9836-3261)
- Reinhard J. Maurer (ORCID: https://orcid.org/0000-0002-3004-785X)
- A. Velmurugan (ORCID: https://orcid.org/0000-0003-3165-9126)
- Hafiz Ghulam Abbas (ORCID: https://orcid.org/0000-0002-1734-1296)
- Byeong Jun (ORCID: https://orcid.org/0000-0002-8703-2309)
- Geonhwa Kim (ORCID: https://orcid.org/0000-0002-6203-7613)
- Stefan Ringe (ORCID: https://orcid.org/0000-0002-7804-1406)
- Benedikt P. Klein (ORCID: https://orcid.org/0000-0002-6205-8879)
- Beomgyun Jeong (ORCID: https://orcid.org/0000-0003-3890-1464)
- Young Dok Kim (ORCID: https://orcid.org/0000-0003-1138-5455)
- Chang Hyuck Choi (ORCID: https://orcid.org/0000-0002-2231-6116)
- Dongwoo Kim (ORCID: https://orcid.org/0000-0002-6515-5260)
- Ki-Jeong Kim (ORCID: https://orcid.org/0000-0001-9233-3096)
Institutions
- École Nationale Supérieure de Chimie de Montpellier (FR)
- Pohang University of Science and Technology (KR)
- Centre National de la Recherche Scientifique (FR)
- Korea University (KR)
- Université de Montpellier (FR)
- University of Warwick (GB)
- Centre National pour la Recherche Scientifique et Technique (CNRST) (MA)
- Institut Charles Gerhardt Montpellier (FR)
- Advanced Institute of Convergence Technology (KR)
- Korea Basic Science Institute (KR)
- Sungkyunkwan University (KR)
Publication Details
- Journal
- Angewandte Chemie International Edition
- Published
- 2025-01-09
- DOI
- https://doi.org/10.1002/anie.202420673
- Citations
- 4
- Primary Topic
- Catalytic Processes in Materials Science
- Type
- article
- Field-Weighted Citation Impact
- 2.07
Funders
- UK Research and Innovation
- National Research Foundation
- Pohang University of Science and Technology
- Korea Institute of Science and Technology
- Korea Institute of Science and Technology Information
- Korea Basic Science Institute
- National Research Foundation of Korea
- Ministry of Science and ICT, South Korea
- National Supercomputing Center, Korea Institute of Science and Technology Information