溶胶凝胶和化学镀法制备超细CoAl_2O_4粉体的研究

Study of preparation of cobalt aluminate by sol-gel process and electroless plating

本研究用溶胶凝胶法和化学镀法两种方法制备超细CoAl_2O_4粉体,并且利用XRD,SEM,EDX,DTA等手段进行了检测。结果表明两种方法制备的粉体有相同的尖晶石转变温度;溶胶凝胶法制备的粉体成分严格符合化学计量比,化学镀法制备的粉体中Al是过量的。与溶胶凝胶法相比,用化学镀法来制备的粉体粒度小而且均匀一致,比表面积大,可以很好地控制粉体的粒度和组成。在化学镀制备工艺下,粉体催化剂的反应接触面积较大,有可能获得较高的催化效率;而且用便宜的Al_2O_3部分替代了昂贵的CoAl_2O_4降低了成本,说明化学镀法是一种制备超细CoAl_2O_4粉体的高效方法。

Cobalt aluminate has been prepared by two different methods -- sol-gel process and electroless plating, and characterized by XRD,SEM,EDX and DTA. The powder prepared by these two methods gain spinel structure at the same tempreture. The powder prepared by sol-gel meets to the stoichiometric proportion of cobalt aluminate., but the element of AI is excessive in the powder prepared by electroless plating. Compared to sol-gel process, preparation of cobalt aluminate by electroless plating can not only gain smaller particle size and larger specific area but also control the particle size of the product and reduce the cost since Al2O3 substitutes for part of COAl2O4 and COAl2O4 is more expensive. So, electroless plating is one effective method of preparing cobalt aluminate.