Electrostatically driven kinetic inverse CO_(2)/C_(2)H_(2) separation in LTA-type zeolites  

作　　者：Yongheng Ren Yang Chen Hongwei Chen Lu Zhang Jiangfeng Yang Qi Shi Lin-Bing Sun Jinping Li Libo Li 

机构地区：[1]College of Chemical Engineering and Technology,State Key Laboratory of Clean and Efficient Coal Utilization,Taiyuan University of Technology,Taiyuan,030024,China [2]State Key Laboratory of Materials-Oriented Chemical Engineering,College of Chemical Engineering,Nanjing Tech University,Nanjing,211816,China

出　　处：《Chinese Journal of Structural Chemistry》2024年第10期27-34,共8页结构化学(英文)

基　　金：support from the National Key R&D Program of China(2022YFB3806802);the National Natural Science Foundation of China(22278287,22278288,and 22090062).

摘　　要：The identical molecular size and similar physical properties of carbon dioxide(CO_(2))and acetylene(C_(2)H_(2))make their adsorptive separation extremely challenging to achieve with most adsorbents.Reports on the separation of CO_(2)and C_(2)H_(2)mixtures by zeolites are even rarer with the mechanism of adsorptive separation requiring further exploration.In this paper,we report that ion modulation of zeolite 5A promotes the difference in kinetic diffusion of CO_(2)and C_(2)H_(2),realizing the inverse separation of zeolite from selective adsorption of C_(2)H_(2)to selective adsorption of CO_(2).Creating a compact pore space restricting the orientation of gas molecules enables charge recognition.The positive electrostatic potential at the pore openings was utilized to hinder the diffusion of C_(2)H_(2)between the cages while ensuring the transfer of CO_(2),increasing their diffusion differences in pore channels and leading to the CO_(2)/C_(2)H_(2)kinetic selectivity of 31.97.Grand canonical Monte Carlo(GCMC)simulation demon-strates that the CO_(2)distribution in K-5A-βis significantly higher than that of C_(2)H_(2).Dynamic breakthrough ex-periments verify the excellent performance of material in practical CO_(2)/C_(2)H_(2)separation,for CO_(2)/C_(2)H_(2)(50/50 and 1/99,V/V)mixtures can be separated in one step,thus directly generating high purity C_(2)H_(2)(>99.95%),which provides a promising thought for the zeolite-based separation of CO_(2)and C_(2)H_(2).

关 键 词：ZEOLITE Carbon dioxide Gas separation Electrostatic potential Kinetic diffusion 

分 类 号：O64[理学—物理化学]