Surface structure characteristics of CuO/Ti₀.₅Sn₀.₅O₂ and its activity for CO oxidation
2012
Dong, Lihui | Liu, Lianjun | Lv, Yuanyuan | Zhu, Jie | Wan, Haiqin | Liu, Bin | Gao, Fei | Wang, Xiaoshu | Dong, Lin | Chen, Yi
CuO/Ti₀.₅Sn₀.₅O₂ catalysts were prepared and characterized by high resolution transmission electron microscope (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible diffuse reflection spectrum (UV–vis DRS), electron paramagnetic resonance (EPR), laser Raman spectra (LRS), in situ infrared spectroscopy (IR), and activity test for CO oxidation. The results indicated that (1) copper oxide is highly dispersed on Ti₀.₅Sn₀.₅O₂ support below its dispersion capacity of 0.85mmol Cu²⁺/100m² Ti₀.₅Sn₀.₅O₂; (2) three types of copper species are present on Ti₀.₅Sn₀.₅O₂, which are isolated Cu²⁺, (CuOCu)²⁺ species, and crystalline CuO, respectively. Of them, the dispersed (CuOCu)²⁺ species are the easiest to be reduced by CO; (3) the catalytic activities of CuO/Ti₀.₅Sn₀.₅O₂ catalysts are related to the state of copper on Ti₀.₅Sn₀.₅O₂ support, and the dispersed (CuOCu)²⁺ species are the primary active component. A surface incorporation model was proposed to explain the CuO dispersion of CuO/Ti₀.₅Sn₀.₅O₂ catalysts.
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