Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Comprehensive Study of Carbon Dioxide Adsorption in the Metal-Organic Frameworks M2(dobdc) (M=Mg, Mn, Fe, Co, Ni, Cu, Zn)

Published

Author(s)

Wendy L. Queen, Matthew Ross Hudson, Eric D. Bloch, Jarad A. Mason, Miguel I. Gonzalez, Jason S. Lee, David Gygi, Joshua D. Howe, Kyuho Lee, Tamim A. Darwish, Michael James, Vanessa K. Peterson, Simon J. Teat, Berend Smit, Jeffrey B. Neaton, Jeffrey R. Long, Craig Brown

Abstract

Analysis of the CO2 adsorption properties of a well-known series of metal-organic frameworks M6d26(dobdc) (dobdc^u4¿6 = 2,5-dioxido-1,4-benzenedicarboxylate; M = Mg, Mn, Fe, Co, Ni, Cu, and Zn) is carried out in tandem with [I]in-situ[/I] structural studies to identify the host-guest interactions that lead to significant differences in isosteric heats of CO2 adsorption. Neutron and X-ray powder diffraction and single crystal X-ray diffraction experiments are used to unveil the site-specific binding properties of CO2 within many of these materials while systematically varying both the amount of CO2 and temperature. Unlike previous studies, we have revealed that CO2 adsorbed at the metal cations exhibits intramolecular angles with minimal deviations from 180°, a finding that indicates a strongly electrostatic and physisorptive interaction with the framework surface and sheds more light on the ongoing discussion regarding whether CO2 adsorbs in a linear or nonlinear geometry. For the weaker CO2 adsorbents, significant elongation of the metal-CO2 distances are observed and diffraction experiments additionally reveal that secondary CO2 adsorption sites, while likely stabilized by the population of the primary adsorption sites, significantly contribute to adsorption behavior at ambient temperature. Density functional theory calculations including van der Waals dispersion quantitatively corroborate and rationalize observations regarding intramolecular CO2 angles and trends in relative geometric properties and heats of adsorption in M2(dobdc)¿CO2 adducts.
Citation
Chemical Science
Volume
5

Keywords

neutron powder diffraction, carbon dioxide separation, metal-organic frameworks

Citation

Queen, W. , Hudson, M. , Bloch, E. , Mason, J. , Gonzalez, M. , Lee, J. , Gygi, D. , Howe, J. , Lee, K. , Darwish, T. , James, M. , Peterson, V. , Teat, S. , Smit, B. , Neaton, J. , Long, J. and Brown, C. (2014), Comprehensive Study of Carbon Dioxide Adsorption in the Metal-Organic Frameworks M<sub>2</sub>(dobdc) (M=Mg, Mn, Fe, Co, Ni, Cu, Zn), Chemical Science, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=916344 (Accessed April 14, 2024)
Created August 27, 2014, Updated October 12, 2021