Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Self-Adjusting Binding Pockets Enhance H2 and CH4 Adsorption in a Uranium-Based-Metal–Organic Framework

Published

Author(s)

Dominik P. Halter, Ryan Alexander Klein, Michael A. Boreen, Benjamin A Trump, Craig Brown, Jeffrey R. Long

Abstract

A new, air-stable, permanently porous uranium(IV) metal–organic framework U(bdc)2 (1, bdc2− = 1,4-benzenedicarboxylate) was synthesized and its H2 and CH4 adsorption properties were investigated. Low temperature adsorption isotherms confirm strong adsorption of both gases in the framework at low pressures. In situ gas-dosed neutron diffraction experiments with different D2 loadings revealed a rare example of cooperative framework contraction (δV = −7.8%), triggered by D2 adsorption at low pressures. This deformation creates two optimized binding pockets for hydrogen (Qst = −8.6 kJ/mol) per pore, in agreement with H2 adsorption data. Analogous experiments with CD4 (Qst = −24.8 kJ/mol) and N,N-dimethylformamide as guests revealed that the binding pockets in 1 adjust by selective framework contractions that are unique for each adsorbent, augmenting individual host-guest interactions. Our results suggest that the strategic combination of binding pockets and structural flexibility in metal–organic frameworks holds great potential for the development of new adsorbents with an enhanced substrate affinity.
Citation
Chemical Science
Volume
11
Issue
26

Keywords

MOF, adsorption
Created July 13, 2020, Updated August 29, 2020