The effect of the carrier material on the intrinsic activity of three catalytic total oxidation reactions, namely CO oxidation and methane and propane combustion, over highly dispersed RuO₂ is studied. The carrier materials are systematically varied from ZrO₂ to CeO₂ using ultrathin CeO₂ films on ZrO₂ particles (CeO₂@ZrO₂) as the linking carrier materials that were subjected to different calcination and redox treatments. CeO₂@ZrO₂ is subjected to annealing to 900 °C, transforming the CeO₂ layer into a mixed Ce_xZr_1−xO₂ layer, and finally, after reductive treatment with H₂ at 950 °C and mild re-oxidation at 500 °C a kappa phase layer is formed on the ZrO₂ core. The catalytic CO oxidation and the propane combustion reveal pronounced dependencies on the carrier material. The variation in propane combustion activity with the carrier material is correlated with the varying surface concentration of vacant surface Ce sites, while the activity in CO oxidation is correlated with the oxygen storage capacity (OSC). Quite in contrast, the intrinsic activity and the apparent activation energy in methane combustion are less affected by the carrier material than in the other two reactions. For comparison we chose rutile TiO₂ as the carrier that is known to disperse RuO₂ quite efficiently, revealing, however, by far the lowest activity in all total oxidation reactions studied, due likely to strong metal–support interaction (SMSI).

中文翻译：

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CeO2基载体材料对RuO2上CO、甲烷和丙烷的总氧化影响的比较研究

研究了载体材料对高度分散的 RuO ₂上三种催化总氧化反应（即 CO 氧化和甲烷和丙烷燃烧）的固有活性的影响。载体材料从 ZrO ₂到 CeO ₂系统地变化，使用ZrO ₂颗粒上的超薄 CeO ₂薄膜（CeO ₂ @ZrO ₂）作为连接载体材料，这些材料经过不同的煅烧和氧化还原处理。CeO ₂ @ZrO ₂退火至 900 °C，将 CeO ₂层转变为混合的 Ce _x Zr _{1− x} O₂层，最后，在 950 °C 下用 H ₂还原处理并在 500 °C 下温和再氧化后，在 ZrO ₂核上形成 kappa 相层。催化 CO 氧化和丙烷燃烧揭示了对载体材料的显着依赖性。丙烷燃烧活性随载体材料的变化与空置表面 Ce 位点的表面浓度变化有关，而 CO 氧化活性与储氧能力 (OSC) 相关。相比之下，与其他两个反应相比，甲烷燃烧中的固有活性和表观活化能受载体材料的影响较小。为了比较，我们选择金红石 TiO ₂作为已知分散 RuO 的载体₂非常有效，然而，揭示了迄今为止研究的所有总氧化反应中最低的活性，这可能是由于强金属 - 载体相互作用（SMSI）。