Yuan Wentao, Zhang Dawei, Ou Yang, Fang Ke, Zhu Beien, Yang Hangsheng, Hansen Thomas W, Wagner Jakob B, Zhang Ze, Gao Yi, Wang Yong
State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, China.
Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800, China.
Angew Chem Int Ed Engl. 2018 Dec 17;57(51):16827-16831. doi: 10.1002/anie.201811933. Epub 2018 Nov 21.
Preventing sintering of supported nanocatalysts is an important issue in nanocatalysis. A feasible way is to choose a suitable support. However, whether the metal-support interactions promote or prevent the sintering has not been fully identified. Now, completely different sintering behaviors of Au nanoparticles on distinct anatase TiO surfaces have been determined by in situ TEM. The full in situ sintering processes of Au nanoparticles were visualized on TiO (101) surface, which coupled the Ostwald ripening and particle migration coalescence. In contrast, no sintering of Au on TiO anatase (001) surface was observed under the same conditions. This facet-dependent sintering mechanism is fully explained by the density function theory calculations. This work not only offers direct evidence of the important role of supports in the sintering process, but also provides insightful information for the design of sintering-resistant nanocatalysts.
防止负载型纳米催化剂的烧结是纳米催化领域的一个重要问题。一种可行的方法是选择合适的载体。然而，金属-载体相互作用是促进还是抑制烧结尚未完全明确。目前，通过原位透射电子显微镜（TEM）已确定了金纳米颗粒在不同锐钛矿型TiO₂表面上完全不同的烧结行为。金纳米颗粒在TiO₂(101)表面上的完整原位烧结过程得以可视化，该过程涉及奥斯特瓦尔德熟化和颗粒迁移聚并。相比之下，在相同条件下未观察到金在TiO₂锐钛矿(001)表面上的烧结现象。这种晶面依赖性烧结机制通过密度泛函理论计算得到了充分解释。这项工作不仅为载体在烧结过程中的重要作用提供了直接证据，也为抗烧结纳米催化剂的设计提供了有见地的信息。
