载钴分子筛的XPS研究

X-ray Photoelcctron Spectroscopy Study on Cobalt-impregnated Zeolites

借助XPS技术研究了浸渍法得到的3种载钴分子筛Co/HY、Co/ZSM-5和Co/HA的表面状态和组成.结果表明,这些分子筛的表面深处都有难被还原的类CoAl_2O_4物种存在,而易被还原的钴羟基化合物覆盖于分子筛的表面.空气焙烧加快了类CoAl_2O_4物种的生成.用H_2还原实验考察了3种载钴分子筛上钴物种与分子筛之间相互作用的程度.

X-ray photoelectron spectroscopy was used to investigate three impregnated zeolites Co/HY, Co/ZSM-5 and Co/HA. It is found that the three zeolites cotain nonreducible CoAl2O4 species in the interior of the zeolies, and the reducible cobalt hydrate on the surface of the zeolites. The calcination process can accelerate the formation fo CoAl2O4 species. The interaction between Co species and zeolites in the three samples of zeolites was investigated by using the H2 reduction experiments. It is shown that the sequence of interaction extent follows. Co/HA > Co/ZSM-5 > Co. HY.