Constructing CuO-CeO2 heterointerfaces for enhanced Low-Temperature CO oxidation and SO2 resistance

CuO-CeO 2 composite catalyst for low temperature CO oxidation was fabricated via an impregnation method. The prepared composite CuO-CeO 2 achieved 50 % and 100 % conversion at approximately ∼ 70℃ and ∼ 110℃ (denoted as T 50 and T 100 ), respectively. The enhanced catalytic activities were attributed to the formation of abundant CuO/CeO 2 heterostructures, which increased the concentration of oxygen vacancies in their lattices. In addition, the pore structure of the CuO-CeO 2 composite has also been optimized during the impregnation synthesis process. Compared with bare CeO 2 , which only possesses micropores, CuO-CeO 2 forms more mesopores on its surface, which assists in reducing the deposition rate of sulfate species on the surface. The SO 2 tolerance of the catalyst and hence its stability towards practical industrial flue gas treatment is significantly promoted. Furthermore, Density Functional Theory (DFT) was also performed to explore the mechanism of CO oxidation on the CuO-CeO 2 . It was found that the oxygen vacancy can be easily formed on the CuO/CeO 2 heterointerfaces; the adsorption energy (ΔG) of CO was therefore decreased to 0.15 eV, much lower than that of bare CeO 2 (0.53 eV). Besides, the center of f electrons of Ce in CeO 2 rises from −0.55 eV to – 1.71 eV by introducing CuO, suggesting that the f electrons in Ce become more active, which is beneficial for CO to adsorb.