Catalytic performance of LaCo_0.5M_0.5O₃ (M=Mn, Cr, Fe, Ni, Cu) perovskite-type oxides and LaCo_0.5Mn_0.5O₃ supported on cordierite for CO oxidation

Catalytic combustion of CO over perovskite-type oxides LaCo_0.5M_0.5O₃ (M=Mn, Cr, Fe, Ni, Cu) and LaCo_0.5Mn_0.5O₃ supported on cordierite were investigated. The catalysts were synthesized by impregnation method with citrate and characterized by XRD, SEM and TPR. The LaCo_0.5Mn_0.5O₃ catalyst showed much higher activity in CO oxidation compared with LaCo_0.5M_0.5O₃ (M=Cr, Fe, Ni, Cu) due to different kinds of valence state and lattice oxygen content. When LaCo_0.5Mn_0.5O₃ was supported on cordierite, the activity was improved significantly. However, calcining temperature and the presence of water vapor affected the catalytic activity due to sintering and competition of H₂O with CO for adsorption, respectively.