Determination of dynamic changes of the supported Pd catalysts under the reaction conditions of CO/Hydrocarbons(HCs) oxidation is of great importance to the development of high performance catalysts for vehicle exhaust purification. Here, we found that Pd/CeO₂ catalysts dominated with either PdO or Ce_1-xPd_xO_2-δ species, obtained by modulating the interaction between the Pd precursors and the CeO₂ support during the preparation, show different dynamic properties under the conditions of CO oxidation and also different deactivation behaviors when C₃H₆ is coexisting. Under the CO oxidation condition, the PdO species can be easily reduced to metallic Pd, whereas the Ce_1-xPd_xO_2-δ species remain mainly as ionic Pd²⁺. In situ IR characterization revealed that the chemical state of Pd species on CeO₂ during CO oxidation was related to their redox properties, which also dramatically affects the role of C₃H₆ and H₂O in the reaction.

确定负载型 Pd 催化剂在 CO/碳氢化合物 (HCs) 氧化反应条件下的动态变化对于开发用于汽车尾气净化的高性能催化剂具有重要意义。在这里，我们发现 Pd/CeO ₂催化剂以 PdO 或 Ce _1-x Pd _x O _2-δ物质为主，通过在制备过程中调节 Pd 前体和 CeO ₂载体之间的相互作用获得，在制备过程中表现出不同的动态性能。 CO氧化条件以及C ₃ H _{6时的不同失活行为}是并存的。在CO氧化条件下，PdO物种可以很容易地还原为金属Pd，而Ce _1-x Pd _x O _2-δ物种主要以离子型Pd ²⁺形式存在。原位红外表征表明，CeO ₂上Pd物质在CO氧化过程中的化学状态与其氧化还原性质有关，这也极大地影响了C ₃ H ₆和H ₂ O在反应中的作用。