草酸脱铝Y沸石的性质

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，这种缺铝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

Properties of Y Zeolite Dealuminated by Oxalic Acid

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.