摘要
用ＥＸＡＦＳ技术研究了不同交换度的和还原、再氧化处理的Ｃｕ－ＺＳＭ－５分子筛中铜离子的精细结构．在ＺＳＭ－５分子筛中，存在两种铜可占据的位置：一种具有饱和的氧配位和较短的铜氧距离，另一种钢氧配位不饱和且铜氧距离较远．离子交换时，铜离子可能优先占据前者，其量低于３０％．这两类铜的催化能力差别甚大，前者几乎无催化分解ＮＯ的活性．
XAFS technique has been used to study the copper local structureof fresh, reduced and reoxidized Cu-ZSM-5 zeolites with different exchange degrees. Two kinds of copper sites in Cu-ZSM-5 have been identified: one has saturated oxygen coordination and shorter Cu-O distance, its content is lower than 30%; another has unsaturated oxygencoordination and longer Cu-O distance. During exchanging process,copper ions may preferably take the former, but, they in this site are inactive for NO decomposition.
基金
国家自然科学基金
关键词
铜离子
精细结构
一氧化氮
催化分解
分子筛
Cu-ZSM-5 zeolite, copper ion, fine structure, EXAFS,nitrogen oxide, decomposition
