Rational Design of a Low-Cost, High-Performance Metal–Organic Framework for Hydrogen Storage and Carbon Capture

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• 作者：Matthew Witman ; Sanliang LingAndrzej Gladysiak ; Kyriakos C. Stylianou ; Berend SmitBen Slater ; Maciej Haranczyk
• 刊名：Journal of Physical Chemistry C
• 出版年：2017
• 出版时间：January 19, 2017
• 年：2017
• 卷：121
• 期：2
• 页码：1171-1181
• 全文大小：616K
• ISSN：1932-7455

文摘

We present the in silico design of a MOF-74 analogue, hereon known as M₂(DHFUMA) [M = Mg, Fe, Co, Ni, Zn], with enhanced small-molecule adsorption properties over the original M₂(DOBDC) series. Constructed from 2,3-dihydroxyfumarate (DHFUMA), an aliphatic ligand which is smaller than the aromatic 2,5-dioxidobenzene-1,4-dicarboxylate (DOBDC), the M₂(DHFUMA) framework has a reduced channel diameter, resulting in higher volumetric density of open metal sites and significantly improved volumetric hydrogen (H₂) storage potential. Furthermore, the reduced distance between two adjacent open metal sites in the pore channel leads to a CO₂ binding mode of one molecule per two adjacent metals with markedly stronger binding energetics. Through dispersion-corrected density functional theory (DFT) calculations of guest–framework interactions and classical simulation of the adsorption behavior of binary CO₂:H₂O mixtures, we theoretically predict the M₂(DHFUMA) series as an improved alternative for carbon capture over the M₂(DOBDC) series when adsorbing from wet flue gas streams. The improved CO₂ uptake and humidity tolerance in our simulations is tunable based upon metal selection and adsorption temperature which, combined with the significantly reduced ligand expense, elevates this material’s potential for CO₂ capture and H₂ storage. The dynamical and elastic stabilities of Mg₂(DHFUMA) were verified by hybrid DFT calculations, demonstrating its significant potential for experimental synthesis.