Li Xin, Shen Wanling, Sun Han, Meng Lingchuang, Wang Bing, Zhan Chenxi, Zhao Bin
College of Chemistry and Chemical Engineering, Henan University of Technology Zhengzhou 450001 P. R. China
RSC Adv. 2020 Sep 1;10(53):32241-32248. doi: 10.1039/d0ra05228k. eCollection 2020 Aug 26.
The capture and storage of the greenhouse gas, CO, has attracted much interest from scientists in recent years. In this work, density functional theory (DFT) was used to study the adsorption of CO in different cation-exchanged molecular sieves. The results show that for the monovalent metal (Li, Na, K, Cu) ion-exchanged molecular sieves (zeolite Y, ZSM-5, CHA and A), the adsorption capacities for CO decrease in the order of Li > Na > K > Cu. Cu-exchanged zeolites are not suitable as adsorbents for CO. For the CO adsorption capacities in different zeolites with the same exchanged cation, the adsorption energy decreases in the order of Y > A > ZSM-5 ≈ CHA for Li-exchanged zeolites, and ZSM-5 still has the lowest CO adsorption energy for both Na- and K-exchanged zeolites. In the cation-exchanged Y zeolites with divalent metals (Be, Mg, Ca and Zn), the CO adsorption performance increases in the order of Zn < Be < Ca < Mg. Thus, Zn-exchanged zeolites are not suitable as adsorbents for CO.
近年来，温室气体一氧化碳（CO）的捕获与储存引起了科学家们的广泛关注。在这项工作中，采用密度泛函理论（DFT）研究了CO在不同阳离子交换分子筛中的吸附情况。结果表明，对于单价金属（Li、Na、K、Cu）离子交换分子筛（Y型沸石、ZSM - 5、CHA和A），CO的吸附容量按Li＞Na＞K＞Cu的顺序降低。铜交换沸石不适合作CO的吸附剂。对于具有相同交换阳离子的不同沸石中的CO吸附容量，Li交换沸石的吸附能按Y＞A＞ZSM - 5≈CHA的顺序降低，而对于Na和K交换沸石，ZSM - 5的CO吸附能仍然最低。在二价金属（Be、Mg、Ca和Zn）离子交换的Y型沸石中，CO吸附性能按Zn＜Be＜Ca＜Mg的顺序增加。因此，锌交换沸石不适合作CO的吸附剂。
