清华大学李隽团队报道载体的金属亲和力决定了金催化剂的烧结。相关研究成果发表在2022年11月3日出版的《美国化学会杂志》。

非均相催化反应期间的烧结是负载金属纳米颗粒催化剂中最臭名昭著的失活渠道之一。因此，了解载体对烧结行为的影响至关重要。

该文中，通过使用原位球差校正透射电子显微镜和计算模型，揭示了金纳米颗粒和各种载体之间的原子尺度动态相互作用。发现与非晶态二氧化硅上的相比，二氧化铈上的Au纳米颗粒具有较小的接触角，并且明显不易移动，尤其是在表面台阶处。与亲水性类似，研究人员认为小纳米颗粒的迁移率起源是由于金属亲和力，这决定了金属和载体材料之间的相互作用。

从头算分子动力学（AIMD）和基于机器学习的深度势分子动力学（DPMD）模拟，直接捕获了二氧化硅表面的聚结过程和金在二氧化铈上的强钉扎。原子尺度上的联合实验和理论结果表明，活性载体和惰性载体的金属亲和力是非均相催化剂烧结和失活的关键描述符。

附：英文原文

Title: Metal Affinity of Support Dictates Sintering of Gold Catalysts

Author: Jin-Cheng Liu, Langli Luo, Hai Xiao, Junfa Zhu, Yang He, Jun Li

Issue&Volume: November 3, 2022

Abstract: Sintering during heterogeneous catalytic reactions is one of the most notorious deactivation channels in catalysts of supported metal nanoparticles. It is therefore critical to understand the effect of support on the sintering behavior. Here, by using in situ aberration-corrected transmission electron microscopy and computational modeling, the atomic-scale dynamic interactions are revealed between Au nanoparticles and various supports. It is found that Au nanoparticles on ceria have a smaller contact angle and are apparently less mobile, especially at surface steps when compared with those on the amorphous silica. Analogous to hydrophilicity, we attribute the origin of mobility of small nanoparticles to metal affinity, which determines the interaction between metal and support material. Ab initio molecular dynamics (AIMD) and machine learning-based deep potential molecular dynamics (DPMD) simulations directly capture a coalescence process on the silica surface and the strong pinning of gold on ceria. The joint experimental and theoretical results on the atomic scale demonstrate the metal affinity of active and inert supports as the key descriptor pertinent to sintering and deactivation of heterogeneous catalysts.

DOI: 10.1021/jacs.2c06785

Source: https://pubs.acs.org/doi/10.1021/jacs.2c06785