Preparation and characterization of nano-rare earth composite materials: application in selectivity catalytic oxidation of ammonia and its cytotoxicity study

The manufacture, physical characterization, environmental applications and cytotoxicity properties of nanocomposites consisting of CuO/CeO₂ nano-rare earth composite materials prepared using the coprecipitation method at molar ratio of 6:4 with aqueous solutions of copper nitrate and cerium nitrate were reported. The performance of the selective catalytic oxidation of ammonia to N₂ (NH₃-SCO) over a CuO/CeO₂ nano-rare earth composite materials in a tubular fixed-bed reactor (TFBR) at temperatures from 423 to 673 K in the presence of oxygen was elucidated. The catalytic redox behavior was determined by cyclic voltammetry (CV). The nanocomposite particles were characterized by TEM, with a tiny particle size around 10 nm with high dispersion phenomena. Further, cell cytotoxicity and the percentage cell survival were determined by using 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethoxyphenol)-2-(4-sulfophenyl)-2H-tetra-zolium (MTS) assay on human lung MRC-5 cell line. Experimental results showed that no apparent cytotoxicity was observed when the MRC-5 was exposed to the CuO/CeO₂ nanocomposite materials.