[论文解读] Competing adsorption of H and CO on Pd-alloy surfaces: Mechanistic insight into the mitigating effect of Cu on CO poisoning

Pernilla Ekborg-Tanner, Paul Erhart|arXiv (Cornell University)|Feb 28, 2026

Catalysts for Methane Reforming被引用 0

一句话总结

论文研究氢气和一氧化碳在基于 Pd 的合金表面的吸附竞争，并从机制层面解释铜如何通过机制视角降低 CO 中毒。

ABSTRACT

Multi-component alloys offer broad tunability for addressing challenges in materials science, but their vast configurational space makes their surface chemistry highly sensitive to operating conditions, for example through adsorption and segregation. Here, we study Pd-Au-Cu alloy surfaces in H$_2$ and CO environments motivated by their use in H technologies, in particular plasmonic H$_2$ sensing, where alloying can mitigate limitations intrinsic to Pd such as hysteresis and CO poisoning. Modeling multicomponent surfaces with multiple adsorbate species under realistic conditions is challenging. To this end, we establish an accurate and efficient framework that combines machine-learned interatomic potentials trained on density functional theory data to generate training data for cluster expansions with effectively no limitations on training set size. By constructing continuous surface phase diagrams for H-CO coadsorption we find that coadsorption under operating conditions is governed primarily by the H coverage during annealing. Au-rich surfaces, formed under H-poor conditions, suppress both CO and H adsorption, while H-rich conditions yield Pd-rich surfaces that maintain higher H coverages compared to Pd at relevant CO partial pressures, indicating improved CO poisoning resistance. This effect is insensitive to relative amounts of Au and Cu, despite experimental evidence of the mitigating effect of specifically Cu on CO poisoning. Kinetic barriers for dilute alloy surfaces indicate that absorption pathways near Au are highly unfavorable, while Cu leave the energetics unchanged compared to pure Pd. This finding suggests that Cu in the surface region provides viable pathways to shuttle H into the material when Pd-dominated paths are blocked by CO.

研究动机与目标

• 了解 H 与 CO 在 Pd-合金表面吸附位点的竞争方式。
• 阐明铜在缓解基于 Pd 的催化剂上 CO 中毒中的作用。
• 提供与催化性能相关的吸附行为的机制性见解。

提出的方法

• 摘要未指明所用方法。

实验结果

研究问题

• RQ1 H 与 CO 在 Pd-合金表面上的吸附竞争机制是什么？
• RQ2 铜如何影响在 Pd-基表面上 CO 中毒的缓解？
• RQ3 哪些机理途径可以解释铜对 CO 吸附缓解作用？

主要发现

• 讨论了铜如何缓解 Pd-合金表面 CO 中毒的机制性见解。
• 研究聚焦于 H 与 CO 的竞争吸附，以理解催化性能。
• 摘要中未给出具体的定量结果。