Abstract
In the pursuit of highly stable and selective metal-organic frameworks (MOFs) for the adsorption of caustic acid gas species, an entire series of rare earth MOFs have been explored. Each of the MOFs in this series (RE-DOBDC; RE = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; DOBDC = 2,5-dihydroxyterepthalic acid) was synthesized in the tetragonal space group I4/m. Crystallized MOF samples, specifically Eu-DOBDC, were seen to have a combination of monodentate and bidentate binding when synthesized under typical reaction conditions, resulting in a contortion of the structure. However, extended crystallization times determined that this binding is kinetically controlled and that the monodentate binding option was crystallographically eliminated by extended reaction times at higher temperatures. Furthermore, this series allows for the direct study of the effect of the metal center on the structure of the of the MOF; herein, the lanthanide metal ionic radii contraction across the periodic table results in a reduction of the MOF pore size and lattice parameters. Scanning electron microscopy-energy-dispersive spectroscopy was used to investigate the stages of crystal growth for these RE-DOBDC MOFs. All MOFs, except Er-DOBDC had a minimum of two stages of growth. These analogues were demonstrated by analysis of neutron diffraction (PND) to exhibit a cooperative rotational distortion of the secondary building unit, resulting in two crystallographically distinct linker sublattices. Computational modeling efforts were used to show distinct differences on acid gas (NO2 and SO2) binding energies for RE-DOBDC MOFs when comparing the monodentate/bidentate combined linker with the bidentate-only linker crystal structures.
| Original language | English |
|---|---|
| Pages (from-to) | 56337-56347 |
| Number of pages | 11 |
| Journal | ACS Applied Materials and Interfaces |
| Volume | 13 |
| Issue number | 47 |
| DOIs | |
| State | Published - Dec 1 2021 |
Funding
This work was supported as part of the Center for Understanding and Control of Acid Gas-Induced Evolution of Materials (UNCAGE-ME), an Energy Frontier Research Center, funded by the US Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences under Award DE-SC0012577. A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions, LLC., a wholly owned subsidiary of Honeywell International Inc., for the US Department of Energy’s National Nuclear Security Administration under contract DE-NA-0003525. This paper describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the US Department of Energy of the United States Government. This manuscript has been coauthored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ).
| Funders | Funder number |
|---|---|
| Center for Understanding and Control of Acid Gas-Induced Evolution of Materials | |
| UNCAGE-ME | |
| U.S. Department of Energy | |
| Office of Science | |
| Basic Energy Sciences | DE-SC0012577 |
| National Nuclear Security Administration | DE-NA-0003525 |
| UT-Battelle | DE-AC05-00OR22725 |
Keywords
- MOF
- NOadsorption
- acid gas
- kinetics
- metal-organic framework
- modeling