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改性Y型分子筛的微孔结构分析
Micropore Structure Analysis of Modified Zeolite Y
【摘要】 对六种不同性质的Y型沸石分子筛进行了吸附等温线的测定,对等温线的脱附支数据进行了微孔分析的计算。对相对压力P/P0≥0.3(孔径r>1.5mm)段,可采用BJH法计算中孔孔径分布;对P/P0≤0.3段,可采用MMP法计算微孔孔径分布。在MMP法中引入了N2分子平均单层厚度tm,减少了计算结果的波动。研究表明,HY具有r=1.5~2.4nm的二次孔,用EDTA和(NH4)2SiF6脱铝的Y型沸石,具有更多更宽分布的二次孔,超稳Y的二次孔一直延伸到r>5nm。
【Abstract】 Isotherms of N2 adsorption on six different zeolite Y samples are determined. From these adsorption data, the calculation for micropore analysis is carried out. For the relative pressure P/P0≥0.3 (pore radium r>1.5 nm), the BJH method is used for the calculation of mesopore size distribution, for P/P0≤0.3, the MMP method is used for the calculation of micropore size distribution. The average value of N2 molecule monolayer thickness tm is used to get more reasonable results in MMP method. The results indicate that HY crystals have secondary pores of r=1.5~2.4 nm. The crystals of zeolite Y dealuminated by EDTA or (NH4)2SiF6 have more secondary pores with a wide distribution. The ultrastable zeolite Y crystals remain a large portion of micropore and also have a considerable portion of secondary pore with much wider distribution, up to r>5 nm.
【Key words】 molecular sieve; pore structure; adsorption; zeolite; secondary pore;
- 【文献出处】 华东化工学院学报 , 编辑部邮箱 ,1993年06期
- 【分类号】TQ420;TQ424
- 【被引频次】3
- 【下载频次】252