<i>In Situ</i> Atomic-Scale Observation of Strong Metal–Support Interaction–Induced Structural Transformations in Pt Nanoparticles Deposited on TiO ₂ : Implications for Catalytic Applications

The catalytic activity of heterogeneous catalysts is significantly influenced by strong metal–support interaction (SMSI), which markedly alters their structure and electronic states. Direct observation of atomic-scale structural changes associated with SMSI can provide critical insights into the catalytic performance enhancements. However, few studies have captured the atomic-scale dynamics under close to realistic conditions. In this study, we integrated atomic-resolution scanning transmission electron microscopy with in situ observations of 1–2 nm Pt nanoparticles on anatase TiO2(101) under quasi-atmospheric and high-temperature conditions, enabling direct visualization of the structural transformations associated with SMSI. Under these conditions, the formation of oxygen vacancies triggered Pt–Ti alloy formation accompanied by a change in the Pt/TiO2 interfacial orientation relationship within the nanoparticles. Our findings provide valuable insights into the atomic-scale mechanisms governing catalytic activity, potentially contributing to the rational design of high-performance catalysts.