Putting an ultrahigh concentration of amine groups into a metal-organic framework for CO 2 capture at low pressures

• Published in: Chemical science (Cambridge) Vol. 7; no. 10; pp. 6528 - 6533
• Main Authors: Liao, Pei-Qin, Chen, Xun-Wei, Liu, Si-Yang, Li, Xu-Yu, Xu, Yan-Tong, Tang, Minni, Rui, Zebao, Ji, Hongbing, Zhang, Jie-Peng, Chen, Xiao-Ming
• Format: Journal Article
• Language: English
• Published: England 19.10.2016
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/C6SC00836D

Tremendous efforts have been devoted to increasing the CO capture performance of porous materials, especially for low CO concentration environments. Here, we report that hydrazine can be used as a diamine short enough to functionalize the small-pore metal-organic framework [Mg (dobdc)] (H dobdc = 2,5-dihydroxyl-1,4-benzenedicarboxylic acid). By virtue of the ultrahigh concentration of free amine groups (6.01 mmol g or 7.08 mmol cm ) capable of reversible carbamic acid formation, the new material [Mg (dobdc)(N H ) ] achieves a series of new records for CO capture, such as single-component isotherm uptakes of 3.89 mmol g or 4.58 mmol cm at the atmospheric CO concentration of 0.4 mbar at 298 K and 1.04 mmol g or 1.22 mmol cm at 328 K, as well as more than a 4.2 mmol g or 4.9 mmol cm adsorption/desorption working capacity under dynamic mixed-gas conditions with CO concentrations similar to those in flue gases and ambient air.