In situ XANES and EXAFS Analysis of Redox Active Fe Center Ionic Liquids
[1];
- Joint Center for Energy Storage Reseach, Albuquerque, NM (United States); Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Power Sources Technology Group
- Univ. of Maine, Orono, ME (United States). Dept. of Physics and Astronomy
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Power Sources Technology Group
We apply in situ X-Ray Absorption Near Edge Spectroscopy (XANES) and Extended X-Ray Absorption Fine Structure (EXAFS) techniques to a metal center ionic liquid undergoing oxidation and reduction in a three electrode spectroscopic cell. Furthermore, the determination of the extent of reduction under negative bias on the working electrode and the extent of oxidation are determined after pulse voltammetry to quiescence. While the ionic liquid undergoes full oxidation, it undergoes only partial reduction, likely due to transport issues on the timescale of the experiment. Nearest neighbor Fe-O distances in the fully oxidized state match well to expected values for similarly coordinated solids, but reduction does not result in an extension of the Fe-O bond length, as would be expected from comparisons to the solid phase. Instead, little change in bond length is observed. Finally, we suggest that this may be due to a more complex interaction between the monodentate ligands of the metal center anion and the surrounding charge cloud, rather than straightforward electrostatics between the metal center and the nearest neighbor grouping.
- Research Organization:
- Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); USDOE Office of Electricity Delivery and Energy Reliability (OE)
- Grant/Contract Number:
- AC04-94AL85000
- OSTI ID:
- 1338380
- Report Number(s):
- SAND2016--12355J; 649726
- Journal Information:
- Electrochimica Acta, Journal Name: Electrochimica Acta Journal Issue: C Vol. 185; ISSN 0013-4686
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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