浙江大学孙文平团队揭示了用于析氢反应的二氧化钛支撑的铂团簇中独特的强金属-支撑相互作用。相关研究成果于2024年5月21日发表在《德国应用化学》。

强金属-载体相互作用（SMSI）对调节金属物种的性质至关重要，但由于在团簇尺度上构建SMSI的困难，亚纳米金属团簇的SMSI行为仍然未知。

该文中，研究人员通过真空退火成功构建了Pt团簇和无定形TiO₂纳米片之间的SMSI，这需要相对较低的温度来避免小团簇的聚集。采用原位扫描透射电子显微镜观察了Pt原子的SMSI行为，首次揭示了退火过程中Pt原子发生的动态重排。

随着非晶TiO₂载体的结晶，最初无序的Pt原子变得有序，在Pt和TiO₂之间形成外延界面。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，从TiO₂到Pt的电子转移占据了Pt 5d轨道，这是Pt/TiO₂在形成SMSI后CO吸附能力消失的原因。

该项工作不仅为在团簇规模上构建SMSI开辟了一条新的途径，而且对独特的SMSI行为提供了深入的理解，这将促进负载型金属团簇在催化应用中的发展。

附：英文原文

Title: Unraveling the Unique Strong Metal-Support Interaction in Titanium Dioxide Supported Platinum Clusters for the Hydrogen Evolution Reaction

Author: Zhouxin Luo, Xiao Han, Zhentao Ma, Bingxing Zhang, Xusheng Zheng, Yongfeng Liu, Mingxia Gao, Guoqiang Zhao, Yue Lin, Hongge Pan, Wenping Sun

Issue&Volume: 2024-05-21

Abstract: 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 TiO2 nanosheets by vacuum annealing, which required 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 TiO2 support, forming an epitaxial interface between Pt and TiO2. Such SMSI state can remain stable in oxidation environment even at 400 °C. Further investigations prove that the electron transfer from TiO2 to Pt occupies the Pt 5d orbitals, which is responsible for the disappeared CO adsorption ability of Pt/TiO2 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.

DOI: 10.1002/anie.202406728

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202406728