Cobalt-chloride- and dextrose-containing silica gels were reduced in situ under nitrogen atmosphere in the temperature range of 600 to 950 °C. Analysis of kinetic data on the in situ reduction shows that, in the temperature range of 600 to 750 °C, the contracting geometry type and, in the temperature range of 800 to 950 °C, the nucleation and growth type of mechanisms remain operative. The shape and size of the reduced cobalt nanoparticles in the silica matrix was studied by examining the transmission electron micrographs of the reduced Co/SiO2 samples. The morphology of the reduced metallic particles was found to be influenced by the change in reduction mechanism.
在 600 至 950 °C 的温度范围内,在氮气环境下对含氯化钴和葡萄糖的二氧化硅凝胶进行了原位还原。对原位还原动力学数据的分析表明,在 600 至 750 °C 的温度范围内,收缩几何型机制仍在起作用,而在 800 至 950 °C 的温度范围内,成核和生长型机制仍在起作用。通过检查还原 Co/SiO2 样品的透射电子显微照,研究了二氧化硅基体中还原钴纳米颗粒的形状和尺寸。研究发现,还原金属颗粒的形态受还原机制变化的影响。