Cerium–zirconium mixed oxides (CZ) containing Cu (CZCu) have very high CO oxidation performance at low temperatures under simulated diesel exhaust conditions; however, CZCu is prone to significant deactivation upon hydrothermal aging. In this work, we discovered that Cu supported on commercial CZ (GMR6) is thermally stable, and after aging Cu/GMR6 shows comparable activity for CO oxidation to the fresh CZCu. GMR6 is more thermally stable than homemade CZ, and Cu/GMR6 shows a smaller decrease of BET surface area than Cu/CZ upon hydrothermal aging. The decrease of the BET surface area of the catalyst is accelerated by the presence of Cu. The presence of La and Pr in the GMR6 support provides high structural stability and enhanced oxygen mobility. The formation of both surface and bulk carbonates during CO oxidation results in the activity decrease of Cu/GMR6. Thermal decomposition of these carbonates fully regenerates Cu/GMR6. The presence of low levels of SO₂ in the feed gas mixture poisons the CO oxidation activity of Cu/GMR6 forming highly stable sulfates on the CZ support.

中文翻译：

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在模拟柴油机排气条件下，用于低温CO氧化的含铜二氧化铈基催化剂的热稳定性得到提高†

含铜的铈锆混合氧化物（CZCu）在模拟柴油机排气条件下，在低温下具有很高的CO氧化性能；但是，CZCu在水热老化后易于明显失活。在这项工作中，我们发现负载在商用CZ（GMR6）上的Cu具有热稳定性，并且在老化之后，Cu / GMR6在CO氧化方面表现出与新鲜CZCu相当的活性。GMR6在热稳定性方面比自制CZ更稳定，而Cu / GMR6在水热老化后的BET表面积减小幅度要小于Cu / CZ。铜的存在促进了催化剂的BET表面积的减少。GMR6载体中La和Pr的存在提供了较高的结构稳定性和增强的氧迁移率。CO氧化过程中形成的表面碳酸盐和块状碳酸盐都会导致Cu / GMR6的活性降低。这些碳酸盐的热分解可完全再生Cu / GMR6。SO含量低的存在₂在进料气体混合物的毒物的Cu / GMR6的CO氧化活性上形成CZ支撑高度稳定的硫酸盐。