Structural and magnetic features of La0.7Sr0.3Mn1−xCoxO3 nano-catalysts for ethane combustion and CO oxidation

Structural, magnetic and catalytic properties of La0.7Sr0.3Mn1−xCoxO3 (x=0.00, 0.25, 0.50, 0.75, 1.00) nano-perovskites prepared by the citrate method are investigated. The structural characterization of the compounds by X-ray powder diffraction and using X׳Pert package and Fullprof program is an evidence for a monoclinic structure (P21/n space group) with x=0.50 and a rhombohedral structure (R-3c space group) for other samples. These results have been confirmed by the FT-IR measurements. Crystallite size of the powders obtained from Halder-Wagner method has been compared with the Scherrer method. The structural and magnetic results suggest the presence of different concentrations of various cations of Co+2, Co+3, Co+4, Mn+4 and Mn+3 in the samples. Activation energy, band gap energy, and electrical conductivity measurements have been employed to explain catalytic performance of the samples. The results of performance tests show that the sample with x=0.25 has the highest catalytic activity for CO oxidation, whereas, the sample with x=0.75 has the highest catalytic activity for C2H6 combustion.