Dispersion of copper oxide supported on
γ-alumina and its sulfation properties
γ-alumina and its sulfation properties
(1. National Engineering Laboratory of Vacuum Metallurgy, School of Metallurgy and Energy Engineering,
Kunming University of Science and Technology, Kunming 650093, China;
2. School of Materials Science and Engineering, Beihang University, Beijing 100083, China)
Kunming University of Science and Technology, Kunming 650093, China;
2. School of Materials Science and Engineering, Beihang University, Beijing 100083, China)
Abstract: CuO/γ-Al2O3 catalysts were prepared by impregnation with different CuO loadings. The dispersion of CuO supported on γ-Al2O3 support was studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), and temperature programmed reduction (TPR). The dispersion threshold of CuO in γ-Al2O3 determined by X-ray quantitative analysis was 0.275 g/g, i.e., 0.275CuAl. Highly dispersed CuO or crystalline CuO would appear on the γ-Al2O3 support when CuO loading was below or more than its dispersion threshold. TPR experiments show that reduction peak temperature ranges of 0.1CuAl and pure CuO are 420−690 °C and 290−380 °C, respectively. 0.1CuAl is not easily reduced due to interaction between CuO and γ-Al2O3. 0.5CuAl shows a two-step reduction range during 210−300 °C and 410−730 °C, which confirms the existence of highly dispersed CuO and crystalline CuO. The sulfation experiments show the optimal CuO loading amount is far below its dispersion threshold, and copper oxide supported on γ-Al2O3 is in the form of submonolayer.
Key words: copper oxide; dispersion; submonolayer