摘要
用红外光谱法测定了混合金属羟基配合物柱撑粘土的表面酸性和表面羟基振动。结果表明，粘土和柱撑粘土均具有Ｌｅｗｉｓ酸和Ｂｒｏｎｓｔｅｄ酸（分别简称Ｌ酸和Ｂ酸）中心，且以Ｌ酸为主；不同柱剂交联的柱撑粘土的表面酸性也有所不同；层间柱是柱撑粘土酸性的重要来源，焙烧后它可转变成氧化物柱并释放出质子而产生Ｌ酸和Ｂ酸中心；柱撑粘土分子筛的羟基谱带主要来自六配位铝，其强度随焙烧温度升高而下降；层间柱的稳定对其表面羟基、Ｂ酸和Ｌ酸均有较大影响。
The surface acidity and hydroxyl vibrations of the pillared clay molecular sievecontaining mixed metal complexes were determined by IR spectra.The results suggest thatclay and pillared clays have more Lewis acid sites than Bronsted acid sites.Their surfaceacidity is varied with the pillaring agents and comes from their pillars,which can betransferred into oxides and release protons and produce Bronsted and Lewis acid sites aftercalcination.The hydroxyl groups(3500-3700 cm-1) are originated mainly from thealuminum located on the octahedral skeleton and their intensities decrease with the increasingtemperature.The stability of the pillars in the pillared clays affects their surface hydroxylgroups and Bronsted and Lewis acid sites.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
1994年第4期27-30,18,共5页
Spectroscopy and Spectral Analysis
关键词
柱撑粘土
分子筛
红外光谱
酸性
Pillared clay,Surface acidity,Infrared spectra
