4A分子筛的吸附性能与孔结构研究  

Adsorption Performance and Pore Structure of 4A Molecular Sieve

作　　者：白彪坤 孟岳 陈叔平[1] BAI Biaokun;MENG Yue;CHEN Shuping(College of Petroleum and Chemical Engineering,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学石油化工学院,兰州730050

出　　处：《硅酸盐通报》2020年第10期3367-3372,共6页Bulletin of the Chinese Ceramic Society

摘　　要：多孔材料的吸附性能与其独特、复杂的孔结构有关。为探究低温低压下4A分子筛的吸附性能,采用静态膨胀法获得了其在77K下对N2、O2、空气的吸附曲线,分析了分子筛对不同吸附质的吸附量存在差异的原因。以N2、CO2、Ar为吸附质,利用气体吸附法来表征4A分子筛的微孔结构。研究结果表明:4A分子筛对O2的吸附量达到1×10^4Pa·L/g,高出N2、空气两个数量级;对于4A分子筛,273K时,CO2是气体吸附法表征其微孔结构的理想吸附质;采用D-R法计算4A分子筛的比表面积更为合理,其比表面积为533.148m^2/g;基于最大吸附量计算的4A分子筛微孔孔容与文献值较为接近;与DFT法相比,H-K法更能准确表征具有微孔的4A分子筛的孔径分布,孔径在1nm以下的孔体积比例占85.42%。The adsorption performance of porous materials is related to its unique and complex pore structure.In order to investigate the adsorption performance of 4A molecular sieves at low temperature and low pressure,the adsorption curves of N2,O2 and air at 77 K were obtained by static expansion method,and the reasons for the difference in adsorption amount were analyzed.With N2,CO2 and Ar as adsorbates,the micropore structure of 4A molecular sieve was characterized by gas adsorption method.The research results show that the adsorption capacity of 4A molecular sieve for O2 reaches 1×10^4 Pa·L/g,which is two orders of magnitude higher than N2 and air.For 4A molecular sieve,CO2 is an ideal adsorbate for characterizing its micropore structure by gas adsorption method at 273 K.It is more reasonable to calculate the specific surface area of 4A molecular sieve by D-R method,and the specific surface area is 533.148 m^2/g.The pore volume of 4A molecular sieve calculated based on the maximum adsorption is close to the literature value.Compared with DFT method,H-K method can more accurately characterize the pore size distribution of 4A molecular sieves with micropores.The proportion of pore volume below 1 nm accounts for 85.42%.

关 键 词：多孔材料 分子筛 吸附性能 微孔 吸附质 

分 类 号：TQ424.2[化学工程]