Pt nanoparticle catalysts supported on a series of TiO₂-SiO₂ composites with different molar ratios were prepared, characterized, and their CO oxidation activities were evaluated under dry and humid conditions. Among the catalysts, Pt/1Ti-3Si showed the best performance under both conditions and potentials for future industrial applications. H₂¹⁸O experiments were designed and the CO₂ composition was calculated to quantify the promotion effect of H₂O, which was highly correlated with the concentration of H₂O and Ti-Si ratio. The XRD, XPS and BET results revealed that the defects on the supports inhibited phase transformation and lattice growth for anatase TiO₂. These defects also led to an increase in the number of acid sites on Pt/TiO₂-SiO₂. The TEM, EDS mapping, and CO chemosorption results indicated that metallic Pt⁰ particles were formed, which was beneficial for CO oxidation during reaction. It was found that the generation of OH from H₂O dissociation and the desorption of OH on TiO₂ were much easier than those on SiO₂, illustrating that the H₂O promotion effect could be controlled by regulating the nature of support. The mechanism of H₂O promotion was proposed by experimental and theoretical methods, which confirms the carboxyl intermediate pathway rather than the formate pathway.

制备、表征了负载在一系列不同摩尔比的 TiO ₂ -SiO ₂复合材料上的 Pt 纳米颗粒催化剂，并在干燥和潮湿条件下评估了它们的 CO 氧化活性。在这些催化剂中，Pt/1Ti-3Si 在未来工业应用的条件和潜力方面均表现出最佳性能。设计H ₂ ¹⁸ O实验，计算CO _{2组成，量化H 2} O的促进作用，这与H ₂ O浓度和Ti-Si比高度相关。XRD、XPS 和 BET 结果表明，载体上的缺陷抑制了锐钛矿 TiO 的相变和晶格生长₂ . 这些缺陷还导致 Pt/TiO ₂ -SiO ₂上酸位的数量增加。TEM、EDS 映射和 CO 化学吸附结果表明形成了金属 Pt ⁰颗粒，这有利于反应过程中的 CO 氧化。发现H ₂ O离解生成OH和OH在TiO ₂上的解吸比在SiO ₂上更容易，说明H ₂ O的促进作用可以通过调节载体的性质来控制。H _{2的作用机理}O 促进是通过实验和理论方法提出的，这证实了羧基中间途径而不是甲酸途径。