The Preparation Of Cobalt And Zinc Oxide Nanocomposites And The Research Of CO Catalytic Oxidation Properties

Catalysts play an enormous role in human production and life, and have been widely used in chemical industry production, research and various life activities. No matter in the scientific theories, or in the industrial reaction, the efficient industrial synthesis and the development of clean energy have great role in improving human economy and protecting survival environment, it all depends on the catalysts. The types of Chinese industrial catalysts can be divided into five big aspects, such as refining catalysts, inorganic catalysts, organic chemical catalysts, catalysts for environmental protection and other catalysts. Among them, the inorganic catalysts have widely application in heterogenous catalytic reaction, for example, gas purification, industrial wastewater degradation, alkylation reaction and industrial Fischer-tropsch reaction. In recent years, scientists and researchers have paid close attention to nano materials in catalytic reaction, which have small particle size, high specific surface and exposure crystal and present higher catalytic efficiency than non-nano sized catalysts.ZnO as a kind of inorganic nano materials, played a great role to the development of functional materials in catalysis, piezoelectric devices, sensors, solar cells and other fields for easily controlling its morphology and crystal face. In addition, nanometer ZnO provides vast development prospects through metal or oxide doping method, heterogeneous composite semiconductor method and surface modification methods, etc.In this paper, we used urea hydrothermal method preparing single crystal porous ZnO nanoplates and transition metal elements doping for researching the ZnO crystallography before and after doping. Moreover, we used the dual template of alkaline zinc carbonate and ZnO to developed a two-step hydrothermal method preparing well dispersive and small size Co3O4 nanoparticles on single crystal porous ZnO nanoplates. The sample was applied to catalytic carbon monoxide process. Paper content is summarized as follows:1. we prepared single crystal porous ZnO nanoplates and four transition metal elements doping ZnO and studied the crystallography changing of ZnO before and after doping. After element doping, the shifting of XRD diffraction peak and the changing of electron diffraction lattice spacing may due to the ZnO lattice expansion and shrink by transition metal ions occupying ZnO lattice, which can affects the crystallography properties of ZnO. Besides, the Ni ions doping porous ZnO nanoplates, partially changed the state of single crystal ZnO.2. we used hydrozincite [Zns(CO3)2(OH)6] precursor and single crystal ZnO nanoplates as dual template to prepare CO3O4 nanoparticles on ZnO with epitaxial relationships. The (220) and (331) crystal plane of CO3O4 parallel orient grows along the (110) and (112) crystal plane of ZnO. Because of the existence of this relationship, CO3O4 nanoparticles can be stable on the surface. From the HRTEM image, CO3O4 nanoparticles have well dispersity and uniform size (about 5nm) on ZnO. The whole synthetic process without any surfactants or organic solvents, it is green and non-polluting. The prepared nanocomposites were applied to carbon monoxide catalytic oxidation and had enhanced performance.