The performance of LaMnxNi1-xO3±δ perovskite mixed oxides (x = 0, 0.1, 0.3, 0.5, 0.7, 0.9, 1) which were prepared by different methods, the Pechini and sol-gel methods in the oxidation of greenhouse gases, CH4 and CO, has been investigated. All samples were characterized using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and N2 adsorption. The results showed that Pechini samples are more active and stable than the sol-gel samples. The partially substituted Ni samples exhibited higher catalytic performance as compared to the LaMnO3 due to the structural defects. But, the high substitution of Ni gradually deforms the structure to rhombohedra, decreases surface area and reduces the number of active Mn sites. Therefore, the catalytic performance passes through a maximum with respect to Ni content. LaMn0.3Ni0.7O3±δ prepared by the Pechini method is more active than others in the oxidation of CH4 and CO.
