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在恶劣的反应环境中支持Au纳米粒子的粒子跳跃和凝聚

Shuoqi Zhang^1,2, Yu Han^1,2, Xiao-Yan Li¹

¹Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.

Journal of the American Chemical Society

|April 22, 2025

概括

为金属纳米粒子 (NP) 发现了一种新的粒子跳跃和凝聚 (PHC) 烧结机制. 这一过程在高温和CO压力下通过气相发生,为催化剂失活提供了新的见解.

科学领域:

材料科学
催化科学
纳米粒子研究

背景情况:

支持金属纳米粒子 (NP) 的烧结在材料和催化中至关重要.
现有的模型包括奥斯瓦尔德成熟 (OR) 和粒子迁移和凝聚 (PMC).
在高气压和高气温下烧结仍然不太清楚.

研究的目的:

在高气压和高温下研究纳米粒子烧结机制.
揭示已经建立的OR和PMC模型之外的新型烧结途径.
了解在恶劣运行条件下催化剂的失效情况.

主要方法:

毫秒级环境动力蒙特卡洛 (EKMC) 模拟.
密度函数理论 (DFT) 的计算.
模拟集中在高CO压力下的金纳米粒子 (Au NPs) 上.

主要成果:

一个独特的穿越空间的烧结机制,粒子跳跃和凝聚 (PHC),被确定.
AuNP从TiO2基质中跳出,通过质量转移在气相中凝聚,并在临界尺寸时重新沉积.
这种PHC机制是由高CO化学潜力驱动的,它有利于NP-CO相互作用而不是NP-基质相互作用.

结论:

在恶劣条件下,PHC机制为NP烧结提供了新的视角.
NP烧结和基板间的催化剂转移可能比以前想象的更容易.
这一发现对于在现实应用中理解催化剂热失效至关重要.

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