Concerning the catalytic field of CO oxidation for designing the cost-effective, stable, and highly active catalysts based on CuO/CeO₂ nanocomposites, in this work, the urea-nitrate combustion method was used to synthesize a series of CuO/CeO₂ catalysts with different CuO loadings (at%Cu) to test their catalytic activity in the CO oxidation, to find out the optimum at%Cu which allows the CuO/CeO₂ composite to perform a higher activity in close to room-like temperature. The at%Cu of 0%, 2.5%, 5.0%, 7.5%, 10%, 20%, 30%, 40%, and 50% were set up to obtain a catalyst series. The resulting catalysts were characterized using EDX, PXRD, SEM, and other methods. It was shown that the CuO loading caused changes in the phase composition (crystalline CeO₂, amorphous or crystalline CuO), the crystallite size (5–10 nm for CeO₂; 20–33 nm for CuO), and the specific surface area (12.2–85.8 m²/g), as well as in the morphological and pore structure. These factors comprehensively influenced the catalytic performance of the samples. The initial temperature (t_i) toward CO oxidation for the best catalyst obtained in this study belonged to the low-temperature region (t_i < 50 °C). The temperature for 50% CO conversion (t_50%) of the best catalysts was less than 100 °C that was much lower compared to pure CeO₂ (t_50% ≈ 31₂ °C). For CO oxidation, the active sites on the surface were correlated with the interactions between copper and cerium oxides; the improvement in catalytic activity is also related to the high concentration of oxygen vacancies or high oxygen storage capacity of the catalysts. Besides, the advantage in the specific surface area of the samples played as one of the decisive factors to the higher CO conversion. It was noted that the increase of CuO loading into the CuO/CeO₂ catalysts exceeded 20% doesn’t lead to a further decrease in the temperature of CO oxidation. Thus, the optimum catalyst composition was determined to be the CuO/CeO₂-20, and its properties were studied by the methods of Raman, XPS, TEM, H₂-TPR, and EDS in detail. Results proved a strong synergistic effect – the coexistence of redox pairs Ce⁴⁺/Ce³⁺-Cu²⁺/Cu⁺, the formation of oxygen vacancies, as well as the presence of superficial lattice oxygen and adsorbed oxygen species leading to improve the catalytic activity of CuO/CeO₂-20 catalyst. Moreover, the stability of the CuO/CeO₂-20 catalyst was investigated and excellent results were obtained. We believe that the activity in CO oxidation of the CuO/CeO₂-20 sample can even be enhanced by doping oxides of the other rare-earth and transition metals, which requires further study.

关于CO氧化的催化领域，以设计基于CuO / CeO ₂纳米复合材料的经济高效，稳定和高活性的催化剂，在这项工作中，使用了硝酸尿素燃烧法合成了一系列的CuO / CeO ₂催化剂用不同的CuO负载量（at％Cu）来测试它们在CO氧化中的催化活性，以找出最佳的at％Cu，从而使CuO / CeO ₂复合材料在接近室温的条件下表现出更高的活性。设定0％，2.5％，5.0％，7.5％，10％，20％，30％，40％和50％的at％Cu以获得催化剂系列。使用EDX，PXRD，SEM和其他方法对所得催化剂进行表征。结果表明，CuO的加载引起相组成的变化（晶体CeO ₂，无定形或晶体CuO），微晶尺寸（CeO ₂为5-10 nm ； CuO为20-33 nm），比表面积（12.2-85.8 m ² / g）以及形态和孔隙结构体。这些因素全面影响了样品的催化性能。本研究中获得最佳催化剂的CO氧化初始温度（t _i）属于低温区域（t _i <50°C）。最佳催化剂的50％CO转化温度（t _50％）低于100°C，这比纯CeO ₂（t _50％ ≈31 ₂°C）。对于CO氧化，表面上的活性位点与铜和铈氧化物之间的相互作用相关。催化活性的提高还与高浓度的氧空位或催化剂的高储氧量有关。此外，样品比表面积的优势是较高CO转化率的决定性因素之一。要指出的是，CuO / CeO ₂催化剂中CuO的增加量超过20％不会导致CO氧化温度的进一步降低。因此，确定最佳催化剂组成为CuO / CeO ₂ -20，并通过拉曼，XPS，TEM，H _2等方法研究了其性能。-TPR和EDS的详细信息。结果证明了很强的协同作用-氧化还原对Ce ⁴⁺ / Ce ³⁺ -Cu ²⁺ / Cu ⁺的共存，氧空位的形成以及表面晶格氧和吸附氧的存在，从而改善了CuO / CeO ₂ -20催化剂的催化活性。此外，研究了CuO / CeO ₂ -20催化剂的稳定性并获得了优异的结果。我们认为，通过掺杂其他稀土金属和过渡金属的氧化物甚至可以提高CuO / CeO ₂ -20样品的CO氧化活性，这需要进一步研究。