Synthesis of nanostructure LaMnO3 and LaCoO3 catalysts and their catalytic activity in oxidation reaction

Nanostructured perovskite-type oxides, LaMnO3 and LaCoO3 have been prepared by three different methods, such as, the sol-gel method, the precipitation method and the amorphous-complexometry method. X-ray diffraction, transmission electron microscopy, and BET surface area measurements have been used to characterize the catalysts. The spectroscopy measurements reveal that there are differences in the formation of the perovskite-type oxides by the different methods. The reduction properties of these two systems have been investigated by using H-TPR. The shape and temperature of TPR peaks depend on the nature of the particle size of the catalyst and the preparation method. On the basis of the results on CO oxidation reaction and TPR, the activity of CO oxidation has been related to the size of the nanostructured perovskite-type ABO(3) crystal.