Dynamic structural and microstructural responses of a metal organic framework type material to carbon dioxide under dual gas flow and supercritical conditions
Andrew J. Allen, Eric J. Cockayne, Winnie Wong-Ng, Jeffrey Culp, Ivan Kuzmenko
The structural and microstructural responses of a model metal-organic framework (MOF) material, Ni(3-Methy-4,4'-bipyridine)[Ni(CN)4] (Ni-BpyMe or PICNIC 21), to CO2 adsorption and desorption are reported for in situ small-angle X-ray scattering (SAXS) and X-ray diffraction (XRD) measurements under different gas pressure conditions for two technologically important cases. These conditions are single or dual gas flow: CO2 with N2, CH4 or H2 at sub-critical CO2 partial pressures and ambient temperatures; and supercritical CO2: static pressures and temperatures adjusted to explore the gas, supercritical fluid and liquid regimes on the CO2 phase diagram. The experimental results are compared with density functional theory (DFT) calculations that seek to predict where CO2 and other gas molecules are accommodated within the sorbent structure as a function of gas pressure conditions, and hence the degree of swelling and contraction in the associated lattice spacings and void spaces. Such predictions illustrate insights that can be gained concerning how such sorbents can be designed or modified to optimize desired gas sorption properties relevant to enhanced gas recovery or to addressing climate change issues through carbon mitigation, or even direct air capture (DAC) of CO2.
, Cockayne, E.
, Wong-Ng, W.
, Culp, J.
and Kuzmenko, I.
Dynamic structural and microstructural responses of a metal organic framework type material to carbon dioxide under dual gas flow and supercritical conditions, Journal of Applied Crystallography, [online], https://doi.org/10.1107/S1600576722012134, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=933450
(Accessed September 30, 2023)