摘要
选用不同粒度的分子筛晶体,在载气(He)对饱和吸附晶体的不同吹扫速度下,测定解吸N_2的浓度,取得一致的结果,证明了扩散过程为晶体内扩散控制。在-90～-20℃范围内测得氮在5A分子筛晶体内扩散系数在6.8×10^(-8)4.4×10^(-7)cm^2/s之间,扩散活化能为8.7kJ/mol。
Diffusion of nitrogen in zeolite 5A crystals was studied with the Zero Length Column (ZLC) technique. Consistency of diffusivities measured from different size samples confirms that desorption rate is controlled by intracrystalline diffusion.Diffusivities and diffusional activation energy were obtained.They are 6.8×10^(-8)～4.4×10^(-7)cm^2·s^(-1) and 8.7kJ.mol^(-1) at-90～-20℃ respectively.
关键词
扩散系数
晶体
分子筛
测定
氮
diffusion coefficients
diffusion in grain
gas chromatography
nitrogen zeolite
