Zhou Lei, Fu Xin-Pu, Wang Ruixing, Wang Cong-Xiao, Luo Feng, Yan Han, He Yang, Jia Chun-Jiang, Li Jun, Liu Jin-Cheng
Center for Rare Earth and Inorganic Functional Materials, School of Materials Science and Engineering & National Institute for Advanced Materials, Nankai University, Tianjin 300350, China.
Key Laboratory for Colloid and Interface Chemistry, Key Laboratory of Special Aggregated Materials, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China.
Sci Adv. 2024 Dec 20;10(51):eadr4145. doi: 10.1126/sciadv.adr4145.
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.
金催化剂这一具有里程碑意义的发现引发了人们对多相催化的浓厚兴趣，但其催化机理仍然难以捉摸。对于负载在二氧化铈表面的金纳米颗粒（NPs）上的一氧化碳氧化反应，人们普遍认为一氧化碳吸附在金颗粒上，而反应发生在金/二氧化铈界面。在此，我们使用深度势能分子动力学模拟研究了在一氧化碳氧化气氛中不同尺寸的负载型金纳米颗粒的动态变化。我们的结果表明，在一氧化碳气氛中，微小金颗粒的结构变得高度无序并发生相变。这种类似液体的结构提供了大量的反应位点，使得一氧化碳在固态金纳米颗粒上而非仅仅在金/二氧化铈界面上能够轻松氧化。催化实验进一步证实了这一结果。这项工作揭示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。
