Abstract
Metal-organic frameworks (MOFs) have emerged as a versatile platform for the rational design of multifunctional materials, combining large specific surface areas with flexible, periodic frameworks that can undergo reversible structural transitions, or "breathing", upon temperature and pressure changes, and through gas adsorption/desorption processes. Although MOF breathing can be inferred from the analysis of adsorption isotherms, direct observation of the structural transitions has been lacking, and the underlying processes of framework reorganization in individual MOF nanocrystals is largely unknown. In this study, we describe the characterization and elucidation of these processes through the combination of in situ environmental transmission electron microscopy (ETEM) and computer simulations. This combined approach enables the direct monitoring of the breathing behavior of individual MIL-53(Cr) nanocrystals upon reversible water adsorption and temperature changes. The ability to characterize structural changes in single nanocrystals and extract lattice level information through in silico correlation provides fundamental insights into the relationship between pore size/shape and host-guest interactions.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 13973-13976 |
| Number of pages | 4 |
| Journal | Journal of the American Chemical Society |
| Volume | 139 |
| Issue number | 40 |
| DOIs | |
| State | Published - Oct 11 2017 |
Funding
This research was supported by the Army Research Office (Grant No. W911NF-15-1-0189). All computer simulations were performed on XSEDE resources supported by the National Science Foundation (Grant No. ACI-1053575) and NERSCC resources supported by the U.S. Department of Energy (DOE) under Contract DE-AC02-05CH11231. LRP is supported by the National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health (Award No. F32EB021859). A portion of the research was performed using the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the DOE, Office of Biological and Environmental Research, and located at Pacific Northwest National Laboratory (PNNL). The EMSL electron microscopy facility was accessed through EMSL Rapid Access Proposal No. 49076. PNNL is operated by Battelle 454 for DOE under Contract DE-AC05-76RL01830. We thank Dr. Libor Kovarik for his assistance in operating the EMSL ETEM gas-manifold system. A portion of this work made use of the EPIC facility at Northwestern University’s NUANCE Center supported by the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205); the MRSEC program (NSF DMR-1121262) at the Materials Resource Center; the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois, through the IIN.
ASJC Scopus subject areas
- Catalysis
- General Chemistry
- Biochemistry
- Colloid and Surface Chemistry