CO Cryo-Sorption as a Surface-Sensitive Spectroscopic Probe of the Active Site Density of Single-Atom Catalysts.

ABSTRACT: 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

SUBMITTER: Jeong B 

PROVIDER: S-EPMC11878345 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature