Development of Functional Metal-organic Frameworks with Microposrosity for Selective Gas Separation

Date

2022

Authors

Shi, Yanshu

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Abstract

Among industrially important gas separations, carbon dioxide removal from pre-combustion and post-combustion processes and industrial paraffin/olefin separation are two essential parts, which are critical for reduction of carbon emissions and manufacturing of many chemicals, fuels, and materials. Conventional gas separation is carried out through liquid extraction or cryogenic distillation, which is both energy-intensive and costly. Adsorptive gas separation is a more energy efficient and economical technique. Recently, the development of CO2-selective adsorbents has shown promising application in hydrocarbon purification and CO2/N2 separations. Traditional adsorbents traditionally suffer from unsatisfactory uptake and poor selectivity for adsorptive gas separation in practice. In this regard, the development of next-generation adsorbents should be capable of realizing high selectivity and large uptake amount (working capacity) for advanced gas separation. The recent development of metal-organic frameworks (MOFs), constructed from the coordination of metal centers and organic linkers, have demonstrated great potentials as selective gas adsorbents. The construction of MOFs is rich in diverse compositions, designable structures, and tunable pore engineering. These properties render MOFs as excellent materials for gas storage and separation applications. MOFs can differentiate certain components like olefin or CO2 from other gas components, such as nitrogen and methane. Up to now, more than 100,000 MOFs have been reported, but only a small portion of MOFs can realize molecular sieving gas separation for adsorptive techniques. In this dissertation, several MOFs have been studied for highly selective CO2 capture: 1) partially desolvated Cu-F-pymo for selective adsorption of CO2 over C2H2; 2) fully activated Cu-F-pymo for size-sieving separation of CO2 from CH4 and N2; 3) a zirconium-based low-cost MOF of Zr-FA for molecular sieving CO2 Separation. Two MOF adsorbents are also developed for ethylene purification from ethane: 1) an ethylene-selective UTSA-280 was prepared from mechanochemical synthesis with high sieving selectivity of C2H4 from C2H6. 2) An ethane-selective Sc-abtc for functional sites favored C2H6 Adsorption over C2H4. These microporous metal−organic framework (MOF) materials have been proposed to systematically study their potential applications in gas adsorption and separation.

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Keywords

Adsorbents, CO2 capture, Gas Separation, materials, microporous, MOFs

Citation

Department

Chemistry