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La_~0.8 Cu_~0.2 MnO_~(3±δ) perovskite-type catalyst for methane combustion prepared through sol-gel process was characterized by X-ray Diffractometry(XRD), X-ray Photoelectron Spectroscopy(XPS) and Scanning Electron Microscopy(SEM). XPS analyses reveal that the surface characteristics of the catalyst are changed. The lattice defects and oxygen vacancies on the catalyst surface are enhanced due to a part of La~3+ being substituted by Cu~2+ . Temperature-programmed-desorption(TPD) and temperature-programmed-reduction(TPR) ~analyses were carried out to study the catalytic behavior. It is found that there are two O_2-desorption peaks at 350℃ and 650℃ in the TPD pattern, and two CH_4-consumption peaks at 420℃ and 750℃ in the TPR patterns respectively, which indicates that the two kinds of oxygen species, so-called α and β oxygen, can react with the methane during catalytic combustion process. The catalytic activity tests were performed in a fixed-bed reactor, and the results show that the T_~1/2 at which the conversion of methane attains 50% of La_~0.8 Cu_~0.2 MnO_~(3±δ) is lower by 55℃ than that of LaMnO_3. This indicates that the catalytic activity of-La_~0.8 Cu_~0.2 MnO_~(3±δ) is increased with partial substitution of Cu~2+ for La~3+ .-
La_ ~ 0.8 Cu_ ~ 0.2 MnO_ ~ (3 ± δ) perovskite-type catalyst for methane combustion prepared by sol-gel process was characterized by X-ray Diffractometry (XRD), X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscopy SEM). XPS analyzes reveal that the surface characteristics of the catalyst are changed. The lattice defects and oxygen vacancies on the catalyst surface are enhanced due to a part of La ~ 3 + being substituted by Cu ~ 2 +. Temperature-programmed-desorption (TPD) and temperature-programmed-reduction (TPR) ~ analyses were carried out to study the catalytic behavior. It is found that there are two O_2-desorption peaks at 350 ° C and 650 ° C in the TPD pattern, and two CH_4 -consumption peaks at 420 ° C and 750 ° C in the TPR patterns respectively, which indicates that the two kinds of oxygen species, so-called α and β oxygen, can react with the methane during catalytic combustion process. performed in a fixed-bed reactor, and the results show that the T_ ~ 1/2 at which the conversion of methane attains 50% of La_ ~ 0.8 Cu_ ~ 0.2 MnO_ ~ (3 ± δ) is lower by 55 ° C than that of LaMnO_3. This indicates that the catalytic activity of -La_ ~ 0.8 Cu_ ~ 0.2 MnO_ ~ (3 ± δ) is increased with partial substitution of Cu ~ 2 + for La ~ 3 + .-