(594e) CO2 Capture in Metal-Organic Frameworks: a Combined Experimental and Modeling Approach

Metal-organic frameworks (MOFs) are a new class of nanoporous materials that have potential applications in separation processes, catalysis, energy storage and sensing. MOFs are inorganic-organic hybrids that are synthesized using organic linker molecules and metal joints that self-assemble to form materials with well-defined pores, high surface areas, and tunable chemical functionalities. By judiciously choosing the metal cluster and organic linker, MOFs can be designed such that the materials have desired magnetic, optical, catalytic, or selective adsorption properties. Concerns about greenhouse gases in the atmosphere have led to significant interest in removing CO2 from the exhaust streams of fossil fuel combustion as the first step in carbon sequestration. Revolutionary advancements are needed to improve the efficiency and cost effectiveness of CO2 capture technologies. We previously showed that in some MOFs the electric field created by co-adsorbed water molecules can significantly increase CO2 uptake and selectivity over nitrogen and methane. [1] Given the large number of possible MOF topologies, linkers, and metal nodes, there are an almost unlimited number of MOFs that could be synthesized. Screening and understanding of the fundamental structure/function relationships are, thus, very important for developing new processes based on MOFs. Most reports to date have focused on only a few MOFs at a time, often only one. We report screening of a diverse collection of 14 MOFs for CO2 capture from flue gas using a combined experimental and modeling approach. Synthesis, characterization, and adsorption measurements are reported for about half of the MOFs, and adsorption data are taken from the literature for the other half. The diversity of the chosen materials will be helpful for improving our understanding of CO2 capture in MOFs.

[1] Yazaydin, A.O., Benin, A.I., Faheem, S.A., Jakubczak, P., Low, J.J., Willis, R.R., Snurr, R.Q. ?Enhanced CO2 Adsorption in Metal-Organic Frameworks via Occupation of Open-Metal Sites by Coordinated Water Molecules?, Chemistry of Materials, 2009, 21, 1425-1430.