Zachman Michael J, Fung Victor, Polo-Garzon Felipe, Cao Shaohong, Moon Jisue, Huang Zhennan, Jiang De-En, Wu Zili, Chi Miaofang
Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
Department of Chemistry, University of California, Riverside, CA, 92521, USA.
Nat Commun. 2022 Jun 6;13(1):3253. doi: 10.1038/s41467-022-30923-2.
Precise control of charge transfer between catalyst nanoparticles and supports presents a unique opportunity to enhance the stability, activity, and selectivity of heterogeneous catalysts. While charge transfer is tunable using the atomic structure and chemistry of the catalyst-support interface, direct experimental evidence is missing for three-dimensional catalyst nanoparticles, primarily due to the lack of a high-resolution method that can probe and correlate both the charge distribution and atomic structure of catalyst/support interfaces in these structures. We demonstrate a robust scanning transmission electron microscopy (STEM) method that simultaneously visualizes the atomic-scale structure and sub-nanometer-scale charge distribution in heterogeneous catalysts using a model Au-catalyst/SrTiO-support system. Using this method, we further reveal the atomic-scale mechanisms responsible for the highly active perimeter sites and demonstrate that the charge transfer behavior can be readily controlled using post-synthesis treatments. This methodology provides a blueprint for better understanding the role of charge transfer in catalyst stability and performance and facilitates the future development of highly active advanced catalysts.
精确控制催化剂纳米颗粒与载体之间的电荷转移为提高多相催化剂的稳定性、活性和选择性提供了独特的机会。虽然可以利用催化剂-载体界面的原子结构和化学性质来调节电荷转移，但对于三维催化剂纳米颗粒，目前还缺少直接的实验证据，这主要是由于缺乏一种高分辨率方法，能够探测并关联这些结构中催化剂/载体界面的电荷分布和原子结构。我们展示了一种强大的扫描透射电子显微镜（STEM）方法，该方法利用金催化剂/钛酸锶载体模型系统，同时可视化多相催化剂中的原子尺度结构和亚纳米尺度电荷分布。使用这种方法，我们进一步揭示了高活性周边位点的原子尺度机制，并证明通过合成后处理可以轻松控制电荷转移行为。这种方法为更好地理解电荷转移在催化剂稳定性和性能中的作用提供了蓝图，并促进了高活性先进催化剂的未来发展。
