氧化铁系乙苯脱氢催化剂的SEM—EDAX研究

用SEM-EDAX 对氧化铁系乙苯脱氢催化剂进行了形貌观察和微区成份分析,结果与 Mubler 等人描述的结构不同,该种催化剂是由外部覆盖层和内部主体层构成。覆盖层是由小块片状晶体堆垛成疏松的层状结构单元,这些结构单元松散地联接起来结成薄层,覆盖在催化剂的表面上,内部主体层是由大量的棒状晶体松散地堆垛而成。分析表明,前者是钾的化合物,是活性相在大气中分解、水解和吸收CO_2生成的产物;后者是α-Fe_2O_3或Fe_3O_4的晶体。

SEM-EDAX Study on Iron Oxide Based Catalyst for Dehydrogenation of Ethylbenzene to Styrene

The iron oxide based catalyst of ethylbenzene dehydrogenation and its precursor without potassium were studied by SEM-EDAX. It was found that although the outer layer surface of the catalyst exhibited a platelet morphology, the inner layer surface was formed by stick crystals. Further studies showed that the platelets were potassium compound and the sticks were iron oxide. Both the deficiencies of the predecessor's work and our viewpoints about the active phase of the catalyst are discussed.