First-Principles Study on Periodic Pt<sub>2</sub>Fe Alloy Surface Models for Highly Efficient CO Poisoning Resistance

Surface and sub-surface atomic configurations are critical for catalysis as they host the active sites governing electrochemical processes. This study employs density functional theory (DFT) calculations and Monte Carlo simulations combined with the cluster-expansion approach to investigate atom dis...

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Bibliographic Details
Main Authors: Junmei Wang, Qingkun Tian, Harry E. Ruda, Li Chen, Maoyou Yang, Yujun Song
Format: Article
Language:English
Published: MDPI AG 2025-08-01
Series:Nanomaterials
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Online Access:https://www.mdpi.com/2079-4991/15/15/1185
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Summary:Surface and sub-surface atomic configurations are critical for catalysis as they host the active sites governing electrochemical processes. This study employs density functional theory (DFT) calculations and Monte Carlo simulations combined with the cluster-expansion approach to investigate atom distribution and Pt segregation in Pt-Fe alloys across varying Pt/Fe ratios. Our simulations reveal a strong tendency for Pt atoms to segregate to the surface layer while Fe atoms enrich the sub-surface region. Crucially, the calculations predict the stability of a periodic Pt<sub>2</sub>Fe alloy surface model, characterized by specific defect structures, at low platinum content and low annealing temperatures. Electronic structure analysis indicates that forming this Pt<sub>2</sub>Fe surface alloy lowers the d-band center of Pt atoms, weakening CO adsorption and thereby enhancing resistance to CO poisoning. Although defect-induced strains can modulate the d-band center, crystal orbital Hamilton population (COHP) analysis confirms that such strains generally strengthen Pt-CO interactions. Therefore, the theoretical design of Pt<sub>2</sub>Fe alloy surfaces and controlling defect density are predicted to be effective strategies for enhancing catalyst resistance to CO poisoning. This work highlights the advantages of periodic Pt<sub>2</sub>Fe surface models for anti-CO poisoning and provides computational guidance for designing efficient Pt-based electrocatalysts.
ISSN:2079-4991