铜分子筛Cu(Ⅰ)物种上吸附CO的漫反射红外光谱

应用漫反射红外光谱测定了不同的铜分子筛经真空自还原后吸附ＣＯ的基频，组频和泛频谱带，结果表明，ＣＯ压力较低时，形成Ｃｕ（Ⅰ）（ＣＯ）吸附物种，其种类与分子筛的结构特性有关。随ＣＯ２压力增高，部分吸附物种转变为Ｃｕ（Ⅰ）（ＣＯ）２，分析Ｃｕ（Ⅰ）（ＣＯ）基频和组频谱带可得到比Ｃ－Ｏ伸缩振动更灵敏的反映Ｃｕ（Ⅰ）和ＣＯ作用的Ｃｕ（Ⅰ）－Ｃ伸缩振动频率。

DIFFUSE REFLECTANCE INFRARED SPECTRA OF CO ADSORBED ON COPPER-EXCHANGED ZEOLITES

Diffuse reflectance infrared spectroscopy was applied to study the fundamentals, combinations and overtones of CO vibrations in the copper carbonyls formed upon CO adsorption on the autoreduced CuZSM5, CuM and CuY zeolites. At low CO pressure, different kinds of Cu()(CO) species are formed depending upon the types of the zeolites. With increasing CO pressure, they are transformed to some extent into Cu()(CO)2. The frequencies of the stretching vibrations of Cu()C bonds in Cu()(CO), which are difficult to obtain directly from infrared measurement, can be derived from the frequencies of the fundamentals and combinations of the CO vibrations. It has been found that they are much more sensitive to the electron donoracceptor properties of the Cu() cations in the formed monocarbonyl species than those of the fundamentals of CO vibrations.