The spillover of oxygen species is fundamentally important in redox reactions, but the spillover mechanism has been less understood compared to that of hydrogen spillover. Herein Sn is doped into TiO₂ to activate low-temperature (<100 °C) reverse oxygen spillover in Pt/TiO₂ catalyst, leading to CO oxidation activity much higher than that of most oxide-supported Pt catalysts. A combination of near-ambient-pressure X-ray photoelectron spectroscopy, in situ Raman/Infrared spectroscopies, and ab initio molecular dynamics simulations reveal that the reverse oxygen spillover is triggered by CO adsorption at Pt²⁺ sites, followed by bond cleavage of Ti-O-Sn moieties nearby and the appearance of Pt⁴⁺ species. The O in the catalytically indispensable Pt-O species is energetically more favourable to be originated from Ti-O-Sn. This work clearly depicts the interfacial chemistry of reverse oxygen spillover that is triggered by CO adsorption, and the understanding is helpful for the design of platinum/titania catalysts suitable for reactions of various reactants.

氧物种的溢出在氧化还原反应中非常重要，但与氢溢出相比，人们对溢出机制的了解较少。在此，将 Sn 掺杂到 TiO _{2中以激活 Pt/TiO 2}催化剂中的低温（<100 °C）反向氧溢出，导致 CO 氧化活性远高于大多数氧化物负载的 Pt 催化剂。近环境压力 X 射线光电子能谱、原位拉曼/红外光谱和从头算分子动力学模拟的组合表明，反向氧溢出是由 CO 在 Pt 2+ 位点的吸附引发的，随后是 Ti 的^键断裂-附近的 O-Sn 部分和 Pt ⁴⁺的出现物种。催化不可或缺的 Pt-O 物种中的 O 在能量上更有利于源自 Ti-O-Sn。这项工作清楚地描述了由 CO 吸附引发的反向氧气溢出的界面化学，理解有助于设计适用于各种反应物反应的铂/二氧化钛催化剂。