Enhancement of CO2binding and mechanical properties upon diamine functionalization of M2(dobpdc) metal-organic frameworks

Autor: Lee, JH, Siegelman, RL, Maserati, L, Rangel, T, Helms, BA, Long, JR, Neaton, JB
Jazyk: angličtina
Rok vydání: 2018
Zdroj: Lee, JH; Siegelman, RL; Maserati, L; Rangel, T; Helms, BA; Long, JR; et al.(2018). Enhancement of CO2binding and mechanical properties upon diamine functionalization of M2(dobpdc) metal-organic frameworks. Chemical Science, 9(23), 5197-5206. doi: 10.1039/c7sc05217k. UC Berkeley: Retrieved from: http://www.escholarship.org/uc/item/22c7n306
DOI: 10.1039/c7sc05217k.
Popis: © 2018 The Royal Society of Chemistry. The family of diamine-appended metal-organic frameworks exemplified by compounds of the type mmen-M2(dobpdc) (mmen = N,N′-dimethylethylenediamine; M = Mg, Mn, Fe, Co, Zn; dobpdc4-= 4,4′-dioxidobiphenyl-3,3′-dicarboxylate) are adsorbents with significant potential for carbon capture, due to their high working capacities and strong selectivity for CO2that stem from a cooperative adsorption mechanism. Herein, we use first-principles density functional theory (DFT) calculations to quantitatively investigate the role of mmen ligands in dictating the framework properties. Our van der Waals-corrected DFT calculations indicate that electrostatic interactions between ammonium carbamate units significantly enhance the CO2binding strength relative to the unfunctionalized frameworks. Additionally, our computed energetics show that mmen-M2(dobpdc) materials can selectively adsorb CO2under humid conditions, in agreement with experimental observations. The calculations further predict an increase of 112% and 124% in the orientationally-averaged Young's modulus E and shear modulus G, respectively, for mmen-Zn2(dobpdc) compared to Zn2(dobpdc), revealing a dramatic enhancement of mechanical properties associated with diamine functionalization. Taken together, our calculations demonstrate how functionalization with mmen ligands can enhance framework gas adsorption and mechanical properties.
Databáze: OpenAIRE