Based On Organic Silicon Monomer Synthesis Of Zno Catalyst Preparation And Catalytic Properties Of The Research

Over the past decades, the promoter studying has attracted great interest due to their significant application for the Rochow reaction. In this paper, urchin-like ZnO microspheres and different sizes of rod-1ke ZnO were successfully prepared via homogeneous precipitation from zinc nitrate and urea, and we used it as a copper catalyst promoter in dimethyldichlorosilane synthesis via Rochow reaction. The synthesis conditions, such as reaction temperature and time, precursor concentration, and the amount of surfactant added were investigated. The ZnO samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TG), and N2adsorption (BET) Compared with commercial ZnO and commercial Zn microspheres, urchin-like ZnO microspheres and different sizes of rod-1ke ZnO showed a better performance in dimethyldichlorosilane synthesis via Rochow reaction. All the experimental results were demonstrated as follows:1. We report the preparation on urchin-like ZnO microspheres by thermal decomposition of hydrozincite. The hydrozincite was synthesized by homogeneous precipitation of zinc nitrate and urea in the presence of a nonionic surfactant polyethylene glycol. The prepared ZnO belongs to the hexagonal wurtzite family, and the diameter is3-8μm, BET surface areas is30.7m2/g. It was found that zinc nitrate concentration, the amount of surfactant and reaction time are the key factors that lead to the formation of urchin-like ZnO microspheres. Compared with commercial Zn microspheres and ZnO nanoparticles, urchin-like ZnO microspheres showed a better performance in dimethyldichlorosilane synthesis via Rochow reaction due to their larger surface area.2. We report the synthesis on rod-like ZnO with different sizes via homogeneous precipitation from zinc nitrate and urea. It was found that zinc nitrate concentration and the reaction temperature were the key factors leading to the formation of rod-like ZnO. The prepared rod-like ZnO belongs to the hexagonal wurtzite family, and the finer rod-like ZnO has the diameter of about200nm and the length about2μm, the thicker rod-like ZnO have the diameter of about400nn and the length about2μm. Compared with commercial Zn microspheres and thicker rod-like ZnO, the finer rod-like ZnO showed a better performance in dimethyldichlorosilane synthesis via Rochow reaction due to their smaller particle size and more surface. 3. Compared with commercial ZnO microspheres and rod-like ZnO, urchin-like ZnO microspheres showed a better performance in dimethyldichlorosilane synthesis via Rochow reaction. Urchin-like ZnO microspheres with the biggest specific surface area showed the highest dimethyldichlorosilane selectivity of85.5%.The study on different morphology and particle size of ZnO as the copper catalyst promoters for the Rochow reaction, reveals the effect of morphology and particle size of ZnO as catalyst promoter in Rochow reaction. Our work would be helpful for developing novel catalyst promoters and understanding the role of promoter in Rochow reaction.