Reference electrode for use in ionic liquids

I&EC 248

Amir H. Saheb, amir.saheb@chemistry.gatech.edu1, Jiri A. Janata, jiri.janata@chemistry.gatech.edu1, and Mira Josowicz, mira.josowicz@chemistry.gatech.edu2. (1) School of Chemistry and Biochemistry, Georgia Institute of Technology, 770 State Street, Atlanta, GA 30332-0400, (2) School of Chemistry and Biochemistry and Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 770 State Street, Atlanta, GA 30332-0400
Use of room temperature ionic liquids, RTIL, in electrochemical experiments poses an inherit difficulty in selecting a reference electrode, due to limited solubility of certain electroactive compounds in the ionic liquid. Taking this into consideration, a reference electrode of the first kind, based on the Ag/Ag+ couple, or of the second kind based on Ag/AgCl reference system was made. The former uses silver-nitrate salt and the latter tetrabutylammonium chloride, both dissolved in acetonitrile and then added to the ionic liquid of choice in concentrations between 1.0M to 0.1M. An ionic contact of the reference system with the test electrolyte was made using a liquid junction internal compartment filled with the same ionic liquid as used for the electrochemical experiment. The performance of the fabricated reference electrodes were tested in the ionic liquid of choice using a ferrocene/ferricenium redox couple. The stability, reproducibility, and temperature behavior of the two reference systems have been characterized in the following ionic liquids: 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, and 1-butyl-3-methylimidazolium hexafluorophosphate.
 

Ionic Liquids: Not Just Solvents Anymore OR Ionic Liquids: Parallel Futures (Sponsored by Green Chemistry and Engineering, Separation Science and Technology and Novel Chemistry with Industrial Applications Sub-Divisions)
1:30 PM-5:45 PM, Tuesday, 28 March 2006 Georgia World Congress Center -- B314, Oral

Division of Industrial and Engineering Chemistry

The 231st ACS National Meeting, Atlanta, GA, March 26-30, 2006