Luo Zhouxin, Han Xiao, Ma Zhentao, Zhang Bingxing, Zheng Xusheng, Liu Yongfeng, Gao Mingxia, Zhao Guoqiang, Lin Yue, Pan Hongge, Sun Wenping
School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310058, P. R. China.
Hefei National Research Center for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, China.
Angew Chem Int Ed Engl. 2024 Aug 5;63(32):e202406728. doi: 10.1002/anie.202406728. Epub 2024 Jul 3.
Strong metal-support interaction (SMSI) is crucial to modulating the nature of metal species, yet the SMSI behaviors of sub-nanometer metal clusters remain unknown due to the difficulties in constructing SMSI at cluster scale. Herein, we achieve the successful construction of the SMSI between Pt clusters and amorphous TiO nanosheets by vacuum annealing, which requires a relatively low temperature that avoids the aggregation of small clusters. In situ scanning transmission electron microscopy observation is employed to explore the SMSI behaviors, and the results reveal the dynamic rearrangement of Pt atoms upon annealing for the first time. The originally disordered Pt atoms become ordered as the crystallizing of the amorphous TiO support, forming an epitaxial interface between Pt and TiO. Such a SMSI state can remain stable in oxidation environment even at 400 °C. Further investigations prove that the electron transfer from TiO to Pt occupies the Pt 5d orbitals, which is responsible for the disappeared CO adsorption ability of Pt/TiO after forming SMSI. This work not only opens a new avenue for constructing SMSI at cluster scale but also provides in-depth understanding on the unique SMSI behavior, which would stimulate the development of supported metal clusters for catalysis applications.
强金属-载体相互作用（SMSI）对于调节金属物种的性质至关重要，然而由于在团簇尺度上构建SMSI存在困难，亚纳米金属团簇的SMSI行为仍然未知。在此，我们通过真空退火成功实现了Pt团簇与非晶TiO纳米片之间SMSI的构建，该过程需要相对较低的温度以避免小团簇的聚集。采用原位扫描透射电子显微镜观察来探究SMSI行为，结果首次揭示了退火后Pt原子的动态重排。随着非晶TiO载体的结晶，原本无序的Pt原子变得有序，在Pt和TiO之间形成了外延界面。这种SMSI状态即使在400 °C的氧化环境中也能保持稳定。进一步的研究证明，电子从TiO转移到Pt占据了Pt的5d轨道，这是形成SMSI后Pt/TiO的CO吸附能力消失的原因。这项工作不仅为在团簇尺度上构建SMSI开辟了一条新途径，还提供了对独特SMSI行为的深入理解，这将推动负载型金属团簇在催化应用中的发展。
