Home » Posts filed under MOFs
U. Jeong,
N. A. Dogan,
M. Garai,
T. S. Nguyen, J. F. Stoddart,
C. T. Yavuz*
J. Am. Chem. Soc., accepted, (2019).
DOI:
10.1021/jacs.9b04198
Making metal-organic frameworks (MOFs) which are stabilized in non-polar media is not as straightforward as their inorganic nanoparticle counterparts, since surfactants penetrate through the porous structures or dissolve the secondary building units (SBUs) through ligand-exchange linker modulator mechanisms. Herein we report that calixarenes stabilize UIO-66 nanoparticles effectively by remaining outside the grains through size exclusion, without pores becoming blocked, all the while providing amphiphilicity that permits the formation of stable colloidal dispersions with much narrower size distributions. Using the UIO-66 dispersed solutions, we showed that smooth films from an otherwise immiscible polystyrene can be made feasibly.
M. Garai,
C. T. Yavuz*
Chem, 5 (4), 750-752 (2019).
Preview
DOI:
10.1016/j.chempr.2019.03.020
Radioactive waste, such as 90Sr, 134Cs, and 131I, from the Fukushima nuclear spill highlighted the need to find effective adsorbents for scrubbing radioactive ions from seawater. In this issue of Chem, Wang and colleagues report a remarkably 90Sr-selective metal-organic framework (SZ-4) that operates with a two-step ion-exchange mechanism and at a wide pH range while being active and intact when tested in actual seawater.
Link to the journal website
V. Rozyyev,
C. T. Yavuz*
Chem, 3, 5, 719-721, (2017).
DOI:
10.1016/j.chempr.2017.10.014
Raw natural gas is predominantly methane (up to 95%) but also contains larger hydrocarbons such as ethane
and propane, acidic gases such as H2S
and CO2, and considerable amounts
of water. In some reserves, H2S can
reach up to 20%, and water content
can be as much as 5%. CO2 in natural
gas, from ppm levels up to 0.5%, is
less significant but noteworthy. Natural
gas treatment starts with the removal of
sludge and gas condensate, followed
by acid gas removal (mostly H2S) by
amine scrubbing. Regenerated H2S is
converted to elemental sulfur via the
Claus process or sulfuric acid by the
wet sulfuric acid process. Sweet (H2S and
CO2-free) natural gas is then dehydrated
with the use of glycols and
then separated from higher alkanes.
Y. Song,
D. Thirion,
S. Subramanian, M. S. Lah,
C. T. Yavuz*
Micropor. Mesopor. Mater., 243, 85-90, (2017).
DOI:
10.1016/j.micromeso.2017.02.021.
Carbon dioxide capture requires stable porous solids like zirconium based metal-organic frameworks (MOFs) in order to make sequestration efforts feasible. Because of the weak binding at low CO
2 partial pressures, oligomeric amines are commonly loaded on porous supports to maximize CO
2 capture while attempting to keep porosity for enhanced diffusion. Here we show the first temperature resolved stability study of linear-amine impregnated UiO-66 by in-situ monitoring of the PXRD pattern. Our findings show that the crystal structure shows a contraction at temperatures as low as 80 °C and deforms considerably above 120 °C, leading to significant doubts about their applicability in CO
2 capture from lean feeds. We confirm that all MOFs need to be thoroughly analyzed at least by means of PXRD at the process relevant temperatures, and reinforced before any plausible plans of application in CO
2 capture.
J. Y. Jung,‡ F. Karadas,‡
S. Zulfiqar,‡ E. Deniz, S. Aparicio, M. Atilhan*,
C. T. Yavuz*, S. M. Han*
Phys. Chem. Chem. Phys., 15, 14319-14327, (2013). [pdf] [
DOI] [WOS] (‡ Equal contribution)
E. Deniz, F. Karadas,
H. A. Patel, S. Aparicio*,
C. T. Yavuz*, M. Atilhan*
Micropor. Mesopor. Mat., 175, 34-42 (2013). [
DOI] [pdf] [WOS]
Metal organic frameworks (such as commercial Basolite®) display significant promise for CO
2 capture and storage. Here, in order to monitor CO
2 capture of Basolite®, we combined high pressure CO
2 adsorption with high-pressure FTIR and Monte Carlo simulations. We found that Basolite® C300 show an unprecedented rise in capture capacity above 25 bars, as predicted by the DFT calculations. Adsorption isotherms were measured up to 200 bar using a state-of-the-art magnetic suspension balance, and in-situ FTIR studies as a function of pressure allowed characterizing the preferential adsorption sites, and their occupancy with increasing pressure. Monte Carlo molecular simulations were used to infer nanoscopic information of the adsorption mechanism, showing the sorbent–CO
2 interactions from structural and energetic viewpoints.
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