Abstract Carbon monoxide oxidation over oxidized Rh surfaces is known to be sensitive to both the oxygen species present as well as the surface temperature. Although CO oxidation on Rh(111) is a prototypical heterogeneously catalyzed oxidation reaction, questions remain about the reactivity of the individual oxygenaceous phases present on the surface. For example, the effects of surface temperature or the duration of CO exposure have not been previously determined on the oxygen-rich, (2 × 1)-O surface adlayer. In this paper, we present results from a study that used a combination of ultra-high vacuum surface science techniques to measure the oxidation of CO by oxygen in the (2 × 1)-O adlayer. The surface temperature during the CO exposure was varied between 100 K and 350 K, and the effect of the surface temperature on CO oxidation was determined for CO exposures between 5 L and 300 L. We observed that the surface temperature had little effect on the CO2 yield or the amount of residual oxygen for CO exposures up to 300 K, but these quantities were reduced after CO exposures above 300 K. We also found that CO oxidation was unchanged by the extent of the CO exposure at both 300 K and 350 K. Taken together, these results show that CO was oxidized over the (2 × 1)-O adlayer during CO exposures above 300 K via a different reaction pathway than the one followed by co-adsorbed O and CO in the (2 × 2)-2O+CO adlayer and that these lower-barrier reactive sites were not regenerated during the CO exposure.

中文翻译：

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吸附氧对Rh(111)的CO氧化的温度依赖性

摘要 已知氧化 Rh 表面上的一氧化碳氧化对存在的氧物质以及表面温度都很敏感。尽管 Rh(111) 上的 CO 氧化是一种典型的非均相催化氧化反应，但表面上存在的各个含氧相的反应性仍然存在问题。例如，先前尚未确定表面温度或 CO 暴露持续时间对富氧 (2 × 1)-O 表面吸附层的影响。在本文中，我们展示了一项研究的结果，该研究结合使用超高真空表面科学技术来测量 (2 × 1)-O 吸附层中氧气对 CO 的氧化。CO 暴露期间的表面温度在 100 K 和 350 K 之间变化，