Preparation and characterization of nanometer perovskite-type complex oxides LaMnO3.15 and their application in catalytic oxidation

LaMnO3+δ nanocrystalline powders were prepared using a new method in which the insoluble carboxyl-containing grafted starch copolymer (ISC) with a 3D tangled network was used to adsorb metal ions by carboxyl and form precursors. The structural components in the ISC and the precursors were identified from Fourier transform infrared spectra (FT-IR) of the samples. Thermogravimetric-differential thermal analysis (TG-DTA) for the precursors gave the detail of their decomposition in the dry air. The crystalline phase of LaMnO3.15 was characterized by X-ray diffraction (XRD). The shape and size distribution of particles were observed by transmission electron microscopy (TEM). The resultant nanoparticles were firstly used as catalysts for selective oxidation in solution and exhibited evidently catalytic activity for oxidation of cinnamaldehyde at moderate temperatures.