Li-LSX分子筛的离子改性及氧氩吸附分离性能

Ion Modification and Oxygen-argon Adsorption Separation Performance of Li-LSX Molecular Sieves

为了探究不同价态阳离子改性Li-LSX分子筛对其氧氩吸附分离性能的影响,采用水溶液离子交换法分别以Ag^+、Ca^2+、Ce^3+为阳离子交换剂制备AgLi-LSX、CaLi-LSX、CeLi-LSX分子筛。通过扫描电镜(SEM)、透射电镜(TEM)、红外光谱(FT-IR)、X射线衍射(XRD)、X射线能谱分析(EDS)、拉曼光谱(Raman)、比表面积分析(BET)等技术手段对分子筛的骨架结构、晶体构型、元素含量、孔结构进行表征分析,考察了改性分子筛的氧氩吸附分离性能。研究结果表明,改性后分子筛的骨架结构、晶体构型没有改变,仍为X型分子筛。在25℃下测定分子筛的氧气和氩气吸附量,CeLi-LSX、CaLi-LSX、AgLi-LSX分子筛的氧气吸附量分别为4.9786mL·g^-1、4.0427mL·g^-1、2.9755mL·g^-1,且三种分子筛的氩气吸附量相近,这表明CeLi-LSX分子筛是一种较好的氧氩吸附分离材料。

Aiming at exploring the effect of modified Li-LSX molecular sieves with diverse valence cation on their oxygen-argon adsorption and separation performance,aqueous solution ion exchange process was employed to prepare AgLi-LSX,CaLi-LSX and CeLi-LSX molecular sieves,with Ag^+,Ca^2+ and Ce^3+ as cationic exchange agents,respectively. Then,the framework structure,crystal configuration,element content and pore structure of the modified molecular sieves were characterized by SEM,TEM,FT-IR,XRD,EDS,Raman and BET technique,and the oxygen-argon adsorption and separation performance of the modified molecular sieves were measured as well. The results indicated that the modified molecular sieves held the same framework structure and crystal configuration with the original molecular sieve,still showing X type. The adsorption amounts of the modified sieves on the oxygen and argon were measured under 25 ℃. As could be seen from the results,CeLi-LSX,CaLi-LSX,AgLi- LSX molecular sieves showed the oxygen adsorption amounts of 4.978 6 mL·g^-1 ,4.042 7 mL·g^-1 ,2.975 5 mL·g^-1 ,respectively,and similar argon adsorption ability. It can be concluded that CeLi-LSX molecular sieve is a favorable materials for oxygen-argon adsorption and separation.