Effect of Sr substitution on structural, redox and catalytic properties of nano-particles La1-xSrxMn0.5Co0.5O3 (x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5) as a catalyst for CO oxidation

Structural features of la(1-x)srxmn0.5co0.5o3 (x = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5) nano-particles were investigated using x-ray powder diffraction and ft-ir spectroscopy. the characterization of compounds by x-ray powder diffraction and using fullprof program show a cubic structure (pm3m space group) for x = 0.0 and a rhombohedra structure (r-3c space group) for the sr substituted la(1-x)srxmn0.5co0.5o3 samples. crystallite size and unit cell parameters decrease with sr substitution. the electrical conductivity of the samples in oxidizing (air) and reducing atmosphere (6%co in nitrogen) and also band gap of the samples has been investigated to interpret the performance of samples. results show that their behavior increases non-uniformly with increase in sr substitution. an increase of sr substitution up to 0.5 increases the performance of the samples and an optimal catalytic activity in the low-temperature conversion of co to co2. it is mainly attributed to a decrease of the crystallite size.