制备方法条件对Au/CeO_2催化CO低温氧化性能研究

用共沉淀法和沉积沉淀法制备了负载型Au/CeO2催化剂,考察了不同制备方法和条件对Au/CeO2催化剂活性的影响。结果表明,制备方法和条件对Au/CeO2催化剂的活性有较大的影响,其中以Na2CO3为沉淀剂的共沉淀法制备的Au/CeO2催化剂活性最佳。最佳制备条件:343K洗涤、473K焙烧、空气预处理。金和部分氧化态的金是活性中心,而且氧化态的金催化活性更好。活性位在金与氧化物载体界面,金粒径越小,金与氧化物载体的接触面越大,活性位越多,催化活性越大。

Effects of Preparation Methods and Conditions on Catalytic Activities of Au/CeO2 Catalyst for CO Low temperature Oxidation

Au/CeO2 was prepared by coprecipitation and deposition-precipitation.It showed that the activities of the catalysts were greatly changed with the preparation methods and conditions.The best preparation conditions of the catalyst were coprecipitation method,Na2CO3 precipitation agent,calcined at 473K,washed at 343K and the pretreatment in air.Results indicated that metallic gold and partly oxidation state of gold is active centre and oxidation state of gold showed better active.Active sites lies at the interface of the support and the gold.The smaller the gold particle is,the bigger the interface of the gold and the support is,the better the Au/CeO2 catalytic active is.