A series of doped rather than supported 3DOM Ce_0.7Fe_0.2M_0.1O₂ and bulk Ce_0.7Fe_0.2Cu_0.1O₂ catalysts were prepared for the CO-SCR reaction. The formation of the 3DOM structure not only improves the reduction performance and surface-active sites but also promotes the generation of more surface-adsorbed oxygen species. Thus, the 3DOM Ce_0.7Fe_0.2Cu_0.1O₂ catalyst shows high CO-SCR activity in the broad operating temperature window of 150–700 °C, with T₅₀ at 150 °C and T₁₀₀ at 350 °C. It also has the highest CO oxidation activity in a series of samples. Moreover, the appearance of Cu⁺–CO species and the fast transition between Ce⁴⁺ and Ce³⁺ (Cu²⁺ + Ce³⁺ ↔ Cu⁺ + Ce⁴⁺) are the reasons why 3DOM Ce_0.7Fe_0.2Cu_0.1O₂ has better catalytic activity than other catalysts at lower temperature. Simultaneously, the oxygen vacancies produced by the reduction of Fe³⁺ → Fe²⁺ and those adjacent to Ce³⁺ are more significant at higher temperatures, and are favorable for the dissociation of NO. The cause of partial deactivation of the optimal catalyst under specific reaction conditions is also discovered, which further confirms the importance of Cu⁺ and number of active sites. Further, the CO-SCR reaction on 3DOM Ce_0.7Fe_0.2Cu_0.1O₂ follows the mechanism of L–H and E–R at low and high temperatures, respectively.

中文翻译：

---

三维有序大孔掺铜铈铁混合氧化物对CO-SCR反应的促进作用机理

制备了一系列掺杂而不是负载的3DOM Ce _0.7 Fe _0.2 M _0.1 O ₂和本体Ce _0.7 Fe _0.2 Cu _0.1 O ₂催化剂用于CO-SCR反应。3DOM结构的形成不仅提高了还原性能和表面活性位，而且促进了更多表面吸附氧的产生。因此，3DOM Ce _0.7 Fe _0.2 Cu _0.1 O ₂催化剂在150-700°C的宽工作温度范围内具有高的CO-SCR活性，T ₅₀在150°C和T ₁₀₀在350°C下。它还在一系列样品中具有最高的CO氧化活性。此外，Cu ⁺ –CO物种的出现以及Ce ⁴⁺和Ce ³⁺（Cu ²⁺ + Ce ³⁺ ↔Cu ⁺ + Ce ⁴⁺）之间的快速转变是3DOM Ce _0.7 Fe _0.2 Cu _0.1 O的原因。₂在较低温度下比其他催化剂具有更好的催化活性。同时，还原Fe ³⁺ →Fe ²⁺以及与Ce ³⁺相邻的氧空位在较高温度下它们更重要，并且对于NO的离解是有利的。还发现了在特定反应条件下最佳催化剂部分失活的原因，这进一步证实了Cu ⁺的重要性和活性位点的数量。此外，在3DOM Ce _0.7 Fe _0.2 Cu _0.1 O ₂上的CO-SCR反应_分别遵循L–H和E–R在低温和高温下的机理。