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Identifying the morphology of Pt nanoparticles for the optimal catalytic activity towards CO oxidation
Nanoscale ( IF 6.7 ) Pub Date : 2022-11-16 , DOI: 10.1039/d2nr04929e
Xinyi Duan 1, 2 , Xiao-Yan Li 1 , Beien Zhu 1, 3, 4 , Yi Gao 1, 3, 4
Affiliation  

The morphology of nanoparticles (NPs) is crucial for determining their catalytic performance. The dramatic changes in the morphology of metal NPs during reactions observed in many in situ experiments pose great challenges for the identification of the geometry for optimal catalytic activities, which arouses the controversial understanding of the reaction mechanism. In this work, taking CO oxidation as a model reaction, we coupled a multiscale structure reconstruction model with kinetic Monte Carlo simulations to study the catalytic performance of the Pt NPs with changing morphology and reaction conditions. Through the quantitative analysis of contour plots for turnover frequencies, we show that the NPs with more well-coordinated sites exhibit optimal activity under CO-rich conditions at higher temperatures, while the reactivity of NPs with more low-coordination sites is optimal under O2-rich conditions at lower temperatures. Further analysis indicates that the competitive adsorption of CO and O2 plays the key role, in which the structure with optimal activity has a closer CO and O coverage. This work not only reconciles the controversy of the active geometry in the experiments, but offers an efficient method to guide the rational design of high-performance catalysts.

中文翻译:

确定 Pt 纳米粒子的形态以获得对 CO 氧化的最佳催化活性

纳米粒子 (NPs) 的形态对于确定其催化性能至关重要。在许多原位观察到的反应过程中金属 NPs 形态的显着变化实验对确定最佳催化活性的几何结构提出了巨大挑战,这引起了对反应机理的有争议的理解。在这项工作中,以 CO 氧化为模型反应,我们将多尺度结构重建模型与动力学蒙特卡罗模拟相结合,以研究 Pt NPs 在不断变化的形态和反应条件下的催化性能。通过周转频率等值线图的定量分析,我们表明具有更多协调良好位点的 NPs 在较高温度下富含 CO 的条件下表现出最佳活性,而具有更多低配位点的 NPs 在 O 2 下的反应性最佳- 较低温度下的丰富条件。进一步分析表明,CO和O 2的竞争吸附起着关键作用,其中活性最佳的结构具有更接近的CO和O覆盖。这项工作不仅调和了实验中活性几何学的争议,而且提供了一种有效的方法来指导高性能催化剂的合理设计。
更新日期:2022-11-16
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