Digging its own Site: Linear Coordination Stabilizes a Pt1/Fe2O3 Single-Atom Catalyst
Abstract
Determining the local coordination of the active site is a pre-requisite for the reliable modeling of single-atom catalysts (SACs). Obtaining such information is difficult on powder-based systems, so much emphasis is placed on density functional theory-based computations based on idealized low-index surfaces of the support. In this work, we investigate how Pt atoms bind to the (1-102) facet of Fe2O3, a common support material in SAC. Using a combination of scanning tunneling microscopy (STM), x-ray photoelectron spectroscopy (XPS), and an extensive computational evolutionary search, we find that Pt atoms significantly reconfigure the support lattice to facilitate a pseudo-linear coordination to surface oxygen atoms. Despite breaking three surface Fe-O bonds, this geometry is favored by 0.84 eV over the best configuration involving an unperturbed support. We suggest that the linear O-Pt-O configuration is common in reactive Pt-based SAC systems because it balances thermal stability with the ability to adsorb reactants from the gas phase, and that extensive structural searches are likely necessary to determine realistic active site geometry in single-atom catalysis.
Keywords
Cite
@article{arxiv.2406.18525,
title = {Digging its own Site: Linear Coordination Stabilizes a Pt1/Fe2O3 Single-Atom Catalyst},
author = {Ali Rafsanjani-Abbasi and Florian Buchner and Faith J. Lewis and Lena Puntscher and Florian Kraushofer and Panukorn Sombut and Moritz Eder and Jiri Pavelec and Erik Rheinfrank and Giada Franceschi and Viktor C. Birschitzky and Michele Riva and Cesare Franchini and Michael Schmid and Ulrike Diebold and Matthias Meier and Georg K. H. Madsen and Gareth S. Parkinson},
journal= {arXiv preprint arXiv:2406.18525},
year = {2025}
}