Effect of TiO₂ doping on methane catalytic combustion deoxidation of CuMnCe/Al₂O₃ catalyst

CuMnCe/TiO₂-Al₂O₃ catalysts with different TiO₂ contents were prepared by the co-impregnation method and characterized by BET, XRD, XPS and H₂-TPR techniques.The catalytic performance in methane deoxidation reaction were investigated using CGK-5A fixed bed reactor.Results showed that doping some TiO₂ in the Al₂O₃ support has no effect on the crystalline structure of the active ingredient.But it can effectively improve Al₂O₃ support sintering resistance and thermal stability, furthermore, it increases content of Ce³⁺/(Ce³⁺+Ce⁴⁺) in the CuMnCe/Al₂O₃ catalysts, which improves the mobility of oxygen.Besides, the content of adsorbed oxygen O_sur/(O_sur+O_latt) and reducible species in the catalyst surface are increased.Thus, effectively, doping some TiO₂ into the Al₂O₃ support improved the catalytic activity of deoxygenation catalyst for methane combustion.CuMnCe/4% TiO₂-Al₂O₃ exhibited optimum catalytic activity and oxygen conversion rate reached 100% at 387℃.