The landmark discovery of gold catalysts has aroused substantial interest in heterogeneous catalysis, yet the catalytic mechanism remains elusive. For carbon monoxide oxidation on gold nanoparticles (NPs) supported on ceria surfaces, it is widely believed that carbon monoxide adsorbs on the gold particles, while the reaction occurs at the gold/ceria interface. Here, we have investigated the dynamic changes of supported gold NPs with various sizes in a carbon monoxide oxidation atmosphere using deep potential molecular dynamics simulations. Our results reveal that the structure of tiny gold particles in carbon monoxide atmospheres becomes highly disordered and undergoes phase transition. Such a liquid-like structure provides massive reactive sites, enabling facile carbon monoxide oxidation on the solid-state gold NP rather than just at the gold/ceria interface. This result is further corroborated by catalytic experiments. This work sheds light on both the size effects and activity in noble metal catalysis and provides insights for the design of more effective nanocatalysts.

中文翻译：

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动态相变决定了负载型金催化剂的粒径效应和活性


金催化剂的里程碑式发现引起了人们对多相催化的浓厚兴趣，但催化机制仍然难以捉摸。对于负载在铈表面的金纳米颗粒 （NP） 上的一氧化碳氧化，人们普遍认为一氧化碳吸附在金颗粒上，而反应发生在金/铈界面处。在这里，我们使用深度电位分子动力学模拟研究了各种尺寸的负载金 NPs 在一氧化碳氧化气氛中的动态变化。我们的结果表明，一氧化碳气氛中微小金颗粒的结构变得高度无序并发生相变。这种液体状结构提供了大量的反应位点，使一氧化碳能够在固态金 NP 上轻松氧化，而不仅仅是在金/二氧化铈界面上。催化实验进一步证实了这一结果。这项工作阐明了贵金属催化中的尺寸效应和活性，并为设计更有效的纳米催化剂提供了见解。