{"title":"Enhanced CO2 Adsorption and Selectivity of CO2/N2 on Amine@ZIF-8 Materials","authors":"Zhijuan Zhang, Pengwei Li, Ting Zhao, Yuanhan Xia","doi":"10.1155/2022/3207986","DOIUrl":null,"url":null,"abstract":"The ZIF-8 crystals were successfully postsynthetically modified using methylamine (MA), ethylenediamine (ED), and N, N\n \n \n \n \n ′\n \n \n \n -dimethylethylenediamine (MMEN) to improve their adsorption performance toward CO2. Results showed that, compared with the original ZIF-8, the BET specific surface area of MA-ZIF-8, MMEN-ZIF-8, and ED-ZIF-8 has increased by 118.2%, 92.0%, and 29.8%, respectively. In addition, their total pore volume increased separately by 130.8%, 100%, and 48.7%. The adsorption capacities of CO2 on the amine-modified ZIF-8 samples followed the order \n \n MA\n −\n ZIF\n −\n 8\n >\n MMEN\n −\n ZIF\n −\n 8\n >\n ED\n −\n ZIF\n −\n 8\n >\n ZIF\n −\n 8\n \n . The CO2 adsorption capacities at 298 K on MA-ZIF-8, MMEN-ZIF-8, and ED-ZIF-8 were increased by 118.2%, 90.2%, and 29.8%, respectively. What is more, the CO2/N2 selectivities calculated using an IAST model of the amine@ZIF-8 samples at 0.01 bar and 298 K were also significantly improved and followed the order \n \n MA\n −\n ZIF\n −\n 8\n \n \n \n 31.4\n \n \n >\n ED\n −\n ZIF\n −\n 8\n \n \n \n 25.1\n \n \n >\n MMEN\n −\n ZIF\n −\n 8\n \n \n \n 14.1\n \n \n >\n ZIF\n −\n 8\n \n \n \n 11.5\n \n \n \n , which increased by 173.0%, 121.4%, and 22.6%, respectively. The isosteric heat of CO2 adsorption (\n \n \n \n Q\n \n \n st\n \n \n \n ) on the MA-ZIF-8, MMEN-ZIF-8, and ED-ZIF-8 all becomes higher, while \n \n \n \n Q\n \n \n st\n \n \n \n of N2 on these samples was slightly lower in comparison with that on the ZIF-8. Furthermore, after six recycle runs of gravimetric CO2 adsorption-desorption on MA-ZIF-8, the adsorption performance of CO2 is still very good, indicating that the MA-ZIF-8 sample has good regeneration performance and can be applied into industrial CO2 adsorption and separation.","PeriodicalId":7315,"journal":{"name":"Adsorption Science & Technology","volume":" ","pages":""},"PeriodicalIF":2.8000,"publicationDate":"2022-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"5","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Adsorption Science & Technology","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1155/2022/3207986","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, APPLIED","Score":null,"Total":0}
引用次数: 5
Abstract
The ZIF-8 crystals were successfully postsynthetically modified using methylamine (MA), ethylenediamine (ED), and N, N
′
-dimethylethylenediamine (MMEN) to improve their adsorption performance toward CO2. Results showed that, compared with the original ZIF-8, the BET specific surface area of MA-ZIF-8, MMEN-ZIF-8, and ED-ZIF-8 has increased by 118.2%, 92.0%, and 29.8%, respectively. In addition, their total pore volume increased separately by 130.8%, 100%, and 48.7%. The adsorption capacities of CO2 on the amine-modified ZIF-8 samples followed the order
MA
−
ZIF
−
8
>
MMEN
−
ZIF
−
8
>
ED
−
ZIF
−
8
>
ZIF
−
8
. The CO2 adsorption capacities at 298 K on MA-ZIF-8, MMEN-ZIF-8, and ED-ZIF-8 were increased by 118.2%, 90.2%, and 29.8%, respectively. What is more, the CO2/N2 selectivities calculated using an IAST model of the amine@ZIF-8 samples at 0.01 bar and 298 K were also significantly improved and followed the order
MA
−
ZIF
−
8
31.4
>
ED
−
ZIF
−
8
25.1
>
MMEN
−
ZIF
−
8
14.1
>
ZIF
−
8
11.5
, which increased by 173.0%, 121.4%, and 22.6%, respectively. The isosteric heat of CO2 adsorption (
Q
st
) on the MA-ZIF-8, MMEN-ZIF-8, and ED-ZIF-8 all becomes higher, while
Q
st
of N2 on these samples was slightly lower in comparison with that on the ZIF-8. Furthermore, after six recycle runs of gravimetric CO2 adsorption-desorption on MA-ZIF-8, the adsorption performance of CO2 is still very good, indicating that the MA-ZIF-8 sample has good regeneration performance and can be applied into industrial CO2 adsorption and separation.
期刊介绍:
Adsorption Science & Technology is a peer-reviewed, open access journal devoted to studies of adsorption and desorption phenomena, which publishes original research papers and critical review articles, with occasional special issues relating to particular topics and symposia.