Enhanced carbon dioxide capture upon incorporation of N,N'-dimethylethylenediamine in the metal–organic framework CuBTTri

Journal Article · Sat Jan 01 04:00:00 EST 2011 · Chemical Science (Online)

DOI:https://doi.org/10.1039/C1SC00354B· OSTI ID:1065624

McDonald, Thomas M. ^[1]; D'Alessandro, Deanna M. ^[2]; Krishna, Rajamani ^[3]; Long, Jeffrey R. ^[1]

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1. Univ. of California-Berkeley, Berkeley, CA (United States)
2. Univ. of Sydney (Australia)
3. Van‘t Hoff Inst. for Molecular Sciences, Univ. of Amsterdam (Netherlands)

High capacity, high selectivity, and low-cost regeneration conditions are the most important criteria by which new adsorbents for post-combustion carbon dioxide capture will be judged. The incorporation of N,N'-dimethylethylenediamine (mmen) into H₃[(Cu₄Cl)₃(BTTri)₈ (CuBTTri; H₃BTTri = 1,3,5-tri(1H-1,2,3-triazol-4-yl)benzene), a water-stable, triazolate-bridged framework, is shown to drastically enhance CO₂ adsorption, resulting in one of the best performing metal–organic frameworks for CO₂ separation reported to date. High porosity was maintained despite stoichiometric attachment of mmen to the open metal sites of the framework, resulting in a BET surface area of 870 m² g^-1. At 25 °C under a 0.15 bar CO₂/0.75 bar N₂ mixture, mmen-CuBTTri adsorbs 2.38 mmol CO₂ g^-1 (9.5 wt%) with a selectivity of 327, as determined using Ideal Adsorbed Solution Theory (IAST). The high capacity and selectivity are consequences of the exceptionally large isosteric heat of CO₂ adsorption, calculated to be -96 kJ mol^-1 at zero coverage. Infrared spectra support chemisorption between amines and CO₂ as one of the primary mechanisms of uptake. Despite the large initial heat of adsorption, the CO₂ uptake was fully reversible and the framework could be easily regenerated at 60 °C, enabling a cycling time of just 27 min with no loss of capacity over the course of 72 adsorption/desorption cycles.

• Research Organization: Energy Frontier Research Centers (EFRC); Center for Gas Separations Relevant to Clean Energy Technologies (CGS)
• Sponsoring Organization: USDOE SC Office of Basic Energy Sciences (SC-22)
• DOE Contract Number: SC0001015
• OSTI ID: 1065624
• Journal Information: Chemical Science (Online), Journal Name: Chemical Science (Online) Journal Issue: 10 Vol. 2; ISSN 2041-6539
• Publisher: Royal Society of Chemistry
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
membrane
carbon capture
materials and chemistry by design
synthesis (novel materials)
synthesis (self-assembly)
synthesis (scalable processing)