Synthesis of Colloidal CuO/γ-Al2O3 by Microemulsion and Its Catalytic Reduction of Aromatic Nitro Compounds

Monodispersed colloidal copper oxide nanoparticles were synthesized by water-in-oil microemulsion using CuCl2 center dot H2O and NaOH. The effect on CuO particle size was studied by varying the water-to-surfactant molar ratio, precursor concentration and molar ratio of NaOH to CuCl2. The morphology, size and size distribution of the particles were studied by transmission electron microscopy and dynamic light scattering. Dispersion destabilization of the colloidal copper oxide nanoparticles was detected by a Turbiscan apparatus. CuO/gamma-Al2O3 catalysts were prepared by dispersing highly stable CuO nanoparticles on gamma-alumina by mechanical stirring. The catalysts were analyzed by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron, and X-ray diffraction, which confirmed the uniform dispersion of CuO on the support. The reduction of the nitro aromatic compounds, 4-nitrophenol, 3-nitrophenol, and 2-nitrophenol, were studied. The CuO/gamma-Al2O3 catalysts were active for the reduction of these nitro aromatic compounds.