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

Subject Areas : Materials synthesis and charachterization

Marzieh  Lotfi ¹ (School of Physics, Damghan University (DU), Damghan, I. R. Iran.)
Ahmad  Gholizadeh ² (School of Physics, Damghan University (DU), Damghan, I. R. Iran.)
Azim  Malekzadeh ³ (School of Chemistry, Damghan University (DU), Damghan, I. R. Iran.)

Received: 2014-06-07 Accepted : 2014-08-24 Published : 2014-12-01

Keywords: Manganite-Cobaltite, Air Pollutants, Conversion of CO to CO2,

Abstract :

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.