摘要
草酸与草酸铵脱铝的Y沸石，具有八面沸石结构和良好的结晶度．羟基红外光谱和吡啶吸附的红外光谱表明，在脱铝Y沸石的骨架中存在着铝空位．这种块铝Y沸石中由3550cm-1表征的小笼羟基更具开放性，但稳定性较差，在升温过程中，它比3640cm－1表征的大笼羟基更易脱除．吡啶与CO双探针分子红外光谱的研究表明，升温脱羟基过程伴随着与Lewis酸有关的非骨架铝的生成．低温N2吸附的结果显示，缺铝Y沸石中还有远远大于铝空位的二次孔存在，这可能是升温过程中结构重排造成的。
The Y zeolite dealundnated by oxalic acid and anunonium oxalate maintained the faujasite structure with a good crystallinity. The OH-IR spectra and chemical analysis showed that there were aluminum vacancies in the framework of the dealundnated Y zeolite. In such a dealuminated Y zeolite, the hydroxyls represented by 3550cm-1 was accessible to pyridine, while not so stable as the hydroxyls represented by 3640cm-1 when they were heated in vacuurn. The IR spectra of double probes of Pyridine and CO illustrate the production of extra-framework alu-nlinum species which are related to Lewis acid sites in the process of dehydroxylation. The results of N2 adsorption at low temperature suggest the existence of secondary pores which are much larger than the aluminum vacancies, and this probably resulted from the structure reconstruction.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
1997年第6期554-559,共6页
Acta Physico-Chimica Sinica
基金
国家自然科学基金
关键词
草酸
Y沸石
脱铝
二次孔
化学脱铝
高硅Y沸石
Dealudrinated Y zeolite, Aluminum vacancy, Secondary pores, Chemical dealuminization
