合成及改性条件对β分子筛孔结构的影响

Effect of Synthesis and Modification Conditions on the Pore Structure of β Molecular Sieve

考察了合成及改性条件对β分子筛孔结构的影响,发现所有的试样均未出现滞后环,这表明所得β分子筛具有均一孔径,其中的孔可解释为晶粒之间的堆积空隙。随着焙烧温度的提高,分子筛的孔径分布变宽,产生了较大的孔;低温(300℃)与高温组合脱胺有利于结晶度的保持。在碱性处理条件下,二次中孔的体积和孔径较小;而酸性条件处理时,二次中孔的体积和孔径都明显增加。

Effect of synthesis and modification conditions on pore structure of β molecular sieve was systematically studied.For all samples no hysteresis loop appeared on adsorption isotherms,which indicated β molecular sieve had an uniform pore structure.The mesopore could be considered as inter-crystal pore.It was found that increasing calcination temperature could widen pore diameter distribution of molecular sieve and form larger pores.Calcination program including low temperature and high temperature was good for maintaining crystallinity of β molecular sieve.On treating with base β molecular sieve had a small volume and diameter of secondary mesopore;but they became larger when treated with acid.