Carbon monoxide and carbon dioxide adsorption on alkali metal cation-exchanged SSZ-13 zeolites

Micro & nano letters

article

Jiawei Feng¹  Yunfeng Hu¹  Qiang Bao¹  Dan Liang¹  Ying Xu¹ 

[1] School of Chemistry and Chemical Engineering, Northeast Petroleum University

关键词: crystal growth from solution;    zeolites;    molecular sieves;    adsorption;    carbon compounds;    ion exchange;    CO2;    CO;    adsorption capacity;    adsorption selectivity;    cation radius;    molecular trapdoor effect;    carbon dioxide adsorption;    alkali metal cation-exchanged SSZ-13 zeolites;    adsorption isotherms;    Toth adsorption models;    Langmuir-Freundlich model;    SSZ-13 molecular sieves;    high silicon SSZ-13 samples;    carbon monoxide adsorption measurements;    chabazite SSZ-13 samples;    hydrothermal method;    CHA skeleton structure;    cation position;    ionic radius;   

DOI  :  10.1049/mnl.2020.0023

学科分类：计算机科学（综合）

来源: Wiley

【 摘 要 】

In this work, chabazite SSZ-13 samples with different cations were synthesised by hydrothermal method and thoroughly analysed using various characterisation techniques. The role of types of cations in CO 2 and CO adsorption measurements was investigated. The adsorption isotherms were fitted by Langmuir, Langmuir-Freundlich and Toth adsorption models, respectively. The result shows that the Langmuir-Freundlich model is the most suitable for the adsorption isotherms of SSZ-13 molecular sieves. The adsorption isotherms of the fitted CO 2 and CO were analysed to study the high silicon SSZ-13 samples of alkali metal cations Li + , Na + , K + and Cs + for ion exchange. The result shows that Na + has the highest adsorption capacity, but the adsorption selectivity is extremely low. K + has the lowest adsorption capacity, but it has excellent adsorption selectivity, which may be attributed to its large cation radius and the special position of cations in CHA skeleton structure, resulting in the formation of ‘molecular trapdoor’ effect. In addition, Cs + has a larger ionic radius than K + , but the adsorption selectivity is not significantly improved, similar to Li + . It can be determined that the ‘molecular trapdoor’ effect has a significant relationship with the position of cations in the framework.

【 授权许可】

CC BY|CC BY-ND|CC BY-NC|CC BY-NC-ND