Effect of partial substitution of lanthanum by strontium or bismuth on structural features of the lanthanum manganite nanoparticles as a catalyst for carbon monoxide oxidation

The effect of partial substitution of lanthanum by strontium or bismuth in LaMnO3 nano-perovskites, i.e. La(1 − x)(Sr or Bi)xMnO3 samples, in which x = 0.0, 0.2 or 0.4, is explored for stoichiometric oxidation of carbon monoxide with air. FT-IR and XRD analyses confirmed the perovskite structure for the catalysts. Average crystallite size of the products was calculated by the data of XRD and average particle size was measured from the TEM micrographs. Small effect is observed on perovskite phase formation of LaMnO3 on substitution of lanthanum with strontium or bismuth. Under similar reaction conditions, small substitution of bismuth has a more positive effect than strontium on lowering the CO oxidation temperature.

► Lanthanum manganite is known as an active catalyst for oxidation.
► Lanthanum can be partially substituted with bismuth in LaMnO3.
► A structural change is not observed on this substitution.
► This substitution has positive effect on LaMnO3 as a catalyst for CO oxidation.