Carbon Dioxide Capture Chemistry of Amino Acid Functionalized Metal–Organic Frameworks in Humid Flue Gas

Abstract

Metal–organic framework-808 has been functionalized with 11 amino acids (AA) to produce a series of MOF-808-AA structures. The adsorption of CO2 under flue gas conditions revealed that glycine- and dl-lysine-functionalized MOF-808 (MOF-808-Gly and -dl-Lys) have the highest uptake capacities. Enhanced CO2 capture performance in the presence of water was observed and studied by using single-component sorption isotherms, CO2/H2O binary isotherm, and dynamic breakthrough measurements. The key to the favorable performance was uncovered by deciphering the mechanism of CO2 capture in the pores and attributed to the formation of bicarbonate as evidenced by 13C and 15N solid-state nuclear magnetic resonance spectroscopy studies. On the basis of these results, we examined the performance of MOF-808-Gly in simulated coal flue gas conditions and found that it is possible to capture and release CO2 by vacuum swing adsorption. MOF-808-Gly was cycled at least 80 times with full retention of performance. This study significantly advances our understanding of CO2 chemistry in MOFs by revealing how strongly bound amine moieties to the MOF backbone create the chemistry and environment within the pores, leading to the binding and release of CO2 under mild conditions without application of heat.

Bifunctional {Pb10K2}–Organic Framework for High Catalytic Activity in Cycloaddition of CO2 with Epoxides and Knoevenagel Condensation

“…Metal–organic frameworks (MOFs), as a novel crystalline hybrid material self-assembled from versatile inorganic secondary building units (SBUs) and functional organic linkers, have attracted widespread attention because of the promising applications in the fields of gas storage/separation, heterogeneous catalysis, energy harvesting, air and water purification, biomedicine, etc. − In general, the nature of the metal ions in inorganic SBUs is essential for the final structures and target properties of the self-assembled MOFs. However, only transition- or lanthanide-based MOFs at present have been well-established and intensively studied. − By contrast, main group metals in the areas of s- and p-block are not paid much attention yet except for the limited reports on the hard acidic cations of Al 3+ , In 3+ , and Mg 2+ , − which should be attributed to the nonclassical coordination and flexible geometry.…”

Isoreticular Double Interpenetrating Copper–Pyrazolate–Carboxylate Frameworks for Efficient CO2 Capture

“…As a new frontier in porous materials, metal–organic frameworks (MOFs) composed of inorganic clusters bridged by organic ligands are an important family of crystalline porous materials. − The intrinsic properties of MOFs, such as porous structures, ultrahigh surface areas, designable structures, and high porosities, endow them with great potential for CO 2 capture and separation. − The ideal MOFs for CO 2 capture should have good capacity and high selectivity, which are realized through two aspects: the pore size-based sieving effect and altering the affinity of the network toward CO 2 . Numerous functionalities, including heteroaromatic N atoms, − amino groups, , open metal sites, and polarizing organic groups, − have been employed with MOFs to make them excellent CO 2 adsorbents.…”

Creating Hyperthin Membranes for Gas Separations

“… 4 It should be noted, however, that significant advances continue to be made with the creation of novel physisorbents and chemisorbents that can selectively capture CO 2 . 5 , 6 …”