COMPARATIVE STUDY OF LA0.7CA0.3MN0.95FE0.05O3 PEROVSKITES PREPARED BY DIFFERENT METHODS AND EFFECT OF PREPARATION ON CATALYTIC ACTIVITY FOR HYDROXYLATION OF BENZENE

Abstract

Magnetic nanoparticles of La0.7Ca0.3Mn0.95Fe0.05O3 perovskites were synthesized by various wet chemical routes, namely co-precipitation, oxalate-gel and citrate-gel methods. Phase formation and crystal structure of the synthesized powders were examined by the X-ray diffraction (XRD) using the Rietveld analysis. The micro- structure was determined by means of scanning electron microscopy (SEM). Infrared transmission spectroscopy revealed that stretching and bending modes are influenced by preparation methods. Synthesis using the oxalate-gel method yielded incomplete reaction irrespective of the calcination temperature adopted. The citrate-gel method yielded better powder properties in terms of particle size and morphology as compared to co-precipitation synthesis. The highest activity for the catalytic oxidation of benzene to phenol in presence of H2O2 was obtained with the sample prepared by the citrate–gel method.