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 electr...