Partial methanol oxidation proceeds with high selectivity to methyl formate (MeFo) on nanoporous gold (npAu) catalysts. As low-coordinated sites on npAu were suggested to affect the selectivity, we experimentally investigated their role in the isothermal selectivity for flat Au(111) and stepped Au(332) model surfaces using a molecular beam approach under well-defined conditions. Direct comparison shows that steps enhance desired MeFo formation and lower undesired overoxidation. DFT calculations reveal differences in oxygen distribution that enhance the barriers to overoxidation at steps. Thus, these results provide an atomic-level understanding of factors controlling the complex reaction network on gold catalysts, such as npAu.

中文翻译：

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甲醇对金的部分氧化：低配位位点如何控制选择性

在纳米多孔金 (npAu) 催化剂上，甲醇部分氧化对甲酸甲酯 (MeFo) 具有高选择性。由于 npAu 上的低配位位点被认为会影响选择性，因此我们在明确的条件下使用分子束方法实验研究了它们在平面 Au(111) 和阶梯状 Au(332) 模型表面等温选择性中的作用。直接比较表明，这些步骤增强了所需的 MeFo 形成并降低了不需要的过度氧化。 DFT 计算揭示了氧气分布的差异，这些差异增强了步骤中过度氧化的屏障。因此，这些结果提供了对控制金催化剂（例如 npAu）上复杂反应网络的因素的原子水平理解。