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采用直接浸渍法、过氧化氢均相氧化沉积法和氨水催化水解法制备了石墨烯负载的铁、钴、镍金属氧化物纳米颗粒.研究了三种沉积方法对颗粒尺寸分布的影响; 采用透射电子显微镜、傅里叶变换红外光谱、X射线衍射和X射线光电子能谱表征了催化剂的形貌与结构.用过氧化氢均相氧化沉淀法可制得粒径分布最均匀的纳米颗粒. 过氧化氢的氧化作用可使石墨烯表面的氧化基团含量最大化, 为纳米颗粒提供了足够的吸附与成核点.氨水加速了金属离子的水解与成核,导致纳米颗粒的粒径增大与不均.以苯甲醇氧化为探针反应考察了催化剂的性能.催化剂的活性按以下顺序逐渐下降:过氧化氢辅助沉积法 > 直接浸渍法 > 氨水催化水解法, 与纳米颗粒尺寸增长趋势一致.纳米催化剂颗粒尺寸与其活性的良好关联性显示, 发展石墨烯负载尺寸可控的纳米催化剂的方法具有重要意义.
The graphene-loaded iron, cobalt and nickel metal oxide nanoparticles were prepared by direct impregnation method, H 2 O 2 homogeneous oxidation deposition method and aqueous ammonia catalytic hydrolysis method. The effects of three deposition methods on particle size distribution were investigated. Electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy were used to characterize the morphology and structure of the catalyst. The most uniform particle size distribution of the nanoparticles was obtained by H 2 O 2 oxidation and precipitation. Oxidation of hydrogen peroxide can maximize the content of oxidized groups on the surface of graphene and provide sufficient adsorption and nucleation sites for the nanoparticles. The ammonia accelerates the hydrolysis and nucleation of the metal ions, resulting in the increase of the particle size of the nanoparticles And inhomogeneity. The performance of the catalyst was investigated by the oxidation of benzyl alcohol to probe reaction. The activity of the catalyst decreased gradually in the following order: hydrogen peroxide-assisted deposition method> direct impregnation method> ammonia-catalyzed hydrolysis method, consistent with the increasing trend of nanoparticle size A good correlation of the nanocatalyst particle size to its activity shows that the method of developing a graphene-supported nanosize catalyst with a controlled size has To sense.