论文部分内容阅读
众所周知,分子筛是一种由SiO_2和Al_2O_3所组成的三维骨架结构的多孔物质,目前在很多催化反应中显示其良好活性。如将少量贵金属担载在分子筛所制得的催化剂,可用於CO加H_2合成汽油和含氧化物的催化过程中。关於这类催化剂的性能,如反应活性、选择性和稳定性等,在很大程度上和催化剂的金属晶粒大小及其在担体上的分布状态有关,而晶粒大小又依赖於催化剂的制备条件,因此人们对催化剂在制备和使用过程中晶粒的变化十分重视。
It is well-known that molecular sieve is a kind of porous substance with three-dimensional framework composed of SiO 2 and Al 2 O 3, which shows its good activity in many catalytic reactions. Such as a small amount of precious metal supported zeolite prepared catalyst can be used for CO plus H 2 synthetic gasoline and oxide containing the catalytic process. The properties of such catalysts such as reactivity, selectivity and stability are to a large extent related to the size of the metal grains of the catalyst and its distribution on the support, which in turn depends on the catalyst preparation Conditions, so people pay attention to the changes of the grains during the preparation and use of the catalyst.