Direct synthesis of an aliphatic amine functionalized metal–organic framework for efficient CO2 removal and CH4 purification. Issue 39 (23rd May 2018)

• Record Type: Journal Article
• Authors: Huang, Ning-Yu; Mo, Zong-Wen; Li, Lu-Jian; Xu, Wei-Jian; Zhou, Hao-Long; Zhou, Dong-Dong; Liao, Pei-Qin; Zhang, Jie-Peng; Chen, Xiao-Ming
• Is Part Of: CrystEngComm. Volume 20:Issue 39(2018)
• Page Start: 5969
• Page End: 5975
• Publication Date: 2018-05-23
• Subjects: Crystals -- Periodicals; Crystal growth -- Periodicals; Crystallography -- Periodicals; Cristaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Cristallographie -- Périodiques; 548
• DOI: 10.1039/c8ce00574e
• Languages: English
• ISSNs: 1466-8033

Abstract

Abstract : An aliphatic amine functionalized MOF was directly synthesized for CO2 adsorption and CH4 purification. Abstract : Porous materials bearing free aliphatic amine groups are powerful adsorbents for carbon dioxide but generally have to be synthesized by complicated, multi-step post-synthetic modification methods due to the high activity of these functional groups. We report a crystal-engineering strategy for such metal–organic frameworks. Reactions of Zn(ii ) ion with diversified coordination modes and bis(4-carboxy-benzyl)amine (H2 bcba) with a secondary aliphatic amine bridge at different temperatures yielded a pair of isomeric frameworks with very similar framework structures but distinctly different local structures, namely α-[Zn(bcba)] (MCF-51 orα-Zn ) with all amino groups coordinated and β-[Zn(bcba)] (MCF-52 orβ-Zn ) with uncoordinated amino groups. Single-component gas adsorption and CO2 /CH4 mixture breakthrough experiments at ambient conditions showed that, the CO2 adsorption ability and CH4 purification performances ofβ-Zn, in terms of CO2 adsorption enthalpy (42 kJ mol −1 ), CO2 /CH4 selectivity (32) and CH4 purity/productivity (1.49 mmol g −1 at 99.999%+), are much higher than those ofα-Zn (CO2 adsorption enthalpy of 17 kJ mol −1, CO2 /CH4 selectivity of 2.9 and CH4 purity/productivity of 0.088 mmol g −1 at 99%+).