Homodiamine-functionalized metal-organic frameworks with a MOF-74-type extended structure for superior selectivity of CO2 over N2Electronic supplementary information (ESI) available. See DOI: 10.1039/c5ta02357b

• Main Authors: Yeon, Je Seon, Lee, Woo Ram, Kim, Nam Woo, Jo, Hyuna, Lee, Hanyeong, Song, Jeong Hwa, Lim, Kwang Soo, Kang, Dong Won, Seo, Jeong Gil, Moon, Dohyun, Wiers, Brian, Hong, Chang Seop
• Format: Article
• Language: English
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c5ta02357b

A porous Mg 2 (dondc) framework (H 4 dondc = 1,5-dioxido-2,6-naphthalenedicarboxylic acid) with open metal sites was prepared and functionalized with primary or secondary diamines (en = ethylenediamine, mmen = N , N ′-dimethylethylenediamine, or ppz = piperazine). The CO 2 adsorption was substantial under post-combustion flue gas conditions as compared to other reported metal-organic frameworks. Interestingly, the IR spectroscopic measurements demonstrated that the CO 2 adsorption mechanism is based on the combination of physisorption and chemisorption. The CO 2 adsorption capacity of 1-mmen was greater than that of 1-en and 1-ppz , which can likely be attributed to the basicity of the free amine groups tethered to the open coordination sites. Ultrahigh selectivity and superior dynamic separation of CO 2 over N 2 were evident in 1-ppz . Such exceptional CO 2 uptake and CO 2 /N 2 selectivity of diamine-functionalized materials hold potential promise for post-combustion CO 2 capture applications. The functionalized MOFs exhibit exceptional CO 2 /N 2 adsorption capacity and selectivity, associated with the basicity of the introduced amine groups.