Electrochemical Kinetics of Ag/Ag+ and TMPD|TMPD+. in the Room-Temperature Ionic Liquid [C4mpyrr][NTf2]; toward Optimizing Reference Electrodes for Voltammetry in RTILs
The voltammetry and kinetics of the Ag|Ag+ system (commonly used as a reference electrode material in both protic/aprotic and RTIL solvents) was studied in the room-temperature ionic liquid N-buty1-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, [C4mpyrr] [NTf2] on a 10 μm diameter Pt elect...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
ACS Publications
2007
|
| _version_ | 1797070433894268928 |
|---|---|
| author | Rogers, E Silvester, D Jones, S Aldous, L Hardacre, C Russell, A Davies, S Compton, R |
| author_facet | Rogers, E Silvester, D Jones, S Aldous, L Hardacre, C Russell, A Davies, S Compton, R |
| author_sort | Rogers, E |
| collection | OXFORD |
| description | The voltammetry and kinetics of the Ag|Ag+ system (commonly used as a reference electrode material in both protic/aprotic and RTIL solvents) was studied in the room-temperature ionic liquid N-buty1-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, [C4mpyrr] [NTf2] on a 10 μm diameter Pt electrode. For the three silver salts investigated (AgOTf, AgNTf2, and AgNO3, where OTf- = trifluoromethanesulfonate, NTf2- = bis(trifluoromethylsulfonyl)imide, and NO 3- = nitrate), the voltammetry gave rise to a redox couple characteristic of a "deposition/stripping" process at the platinum electrode surface. Using potential step chronoamperometry, the diffusion coefficients of AgOTf, AgNTf2, and AgNO3 were found to be 1.05, 1.17, and 5.00 × 10-11 m2 s-1. All three voltammograms were theoretically modeled to reveal surprisingly slow standard electrochemical rate constants, k0, of 2.0, 1.5, and 0.19 × 10-4 cm s-1 respectively for the Ag +|Ag0 couple. As a potentially faster alternative to the Ag|Ag+ system, the voltammetry and kinetics of the TMPD|TMPD + system (where TMPD = N,N,N′,N′-tetramethyl-p- phenylenediamine) was also studied, using neutral TMPD and two TMPD radical cation salts, with BF4- and NTf2- counter anions. Diffusion coefficients for TMPD, TMPD+BF 4-, and TMPD+NTf2- were calculated to be 1.84, 1.35, and 1.43 × 10-11 m2 s-1 respectively, and a k0 value of 2.6-2.8 × 10-3 cm s-1 was obtained from theoretical fitting of the cyclic voltammetry. This number is an order of magnitude larger than that for the Ag|Ag+ system, allowing for the suggestion that the TMPD|TMPD+ system may be more suitable than the Ag|Ag+ system as a redox couple for use in reference electrodes for ionic liquids. © 2007 American Chemical Society. |
| first_indexed | 2024-03-06T22:38:45Z |
| format | Journal article |
| id | oxford-uuid:5ad0e76f-a85a-4d50-8ce1-699321abe6fe |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T22:38:45Z |
| publishDate | 2007 |
| publisher | ACS Publications |
| record_format | dspace |
| spelling | oxford-uuid:5ad0e76f-a85a-4d50-8ce1-699321abe6fe2022-03-26T17:18:08ZElectrochemical Kinetics of Ag/Ag+ and TMPD|TMPD+. in the Room-Temperature Ionic Liquid [C4mpyrr][NTf2]; toward Optimizing Reference Electrodes for Voltammetry in RTILsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:5ad0e76f-a85a-4d50-8ce1-699321abe6feEnglishSymplectic Elements at OxfordACS Publications2007Rogers, ESilvester, DJones, SAldous, LHardacre, CRussell, ADavies, SCompton, RThe voltammetry and kinetics of the Ag|Ag+ system (commonly used as a reference electrode material in both protic/aprotic and RTIL solvents) was studied in the room-temperature ionic liquid N-buty1-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, [C4mpyrr] [NTf2] on a 10 μm diameter Pt electrode. For the three silver salts investigated (AgOTf, AgNTf2, and AgNO3, where OTf- = trifluoromethanesulfonate, NTf2- = bis(trifluoromethylsulfonyl)imide, and NO 3- = nitrate), the voltammetry gave rise to a redox couple characteristic of a "deposition/stripping" process at the platinum electrode surface. Using potential step chronoamperometry, the diffusion coefficients of AgOTf, AgNTf2, and AgNO3 were found to be 1.05, 1.17, and 5.00 × 10-11 m2 s-1. All three voltammograms were theoretically modeled to reveal surprisingly slow standard electrochemical rate constants, k0, of 2.0, 1.5, and 0.19 × 10-4 cm s-1 respectively for the Ag +|Ag0 couple. As a potentially faster alternative to the Ag|Ag+ system, the voltammetry and kinetics of the TMPD|TMPD + system (where TMPD = N,N,N′,N′-tetramethyl-p- phenylenediamine) was also studied, using neutral TMPD and two TMPD radical cation salts, with BF4- and NTf2- counter anions. Diffusion coefficients for TMPD, TMPD+BF 4-, and TMPD+NTf2- were calculated to be 1.84, 1.35, and 1.43 × 10-11 m2 s-1 respectively, and a k0 value of 2.6-2.8 × 10-3 cm s-1 was obtained from theoretical fitting of the cyclic voltammetry. This number is an order of magnitude larger than that for the Ag|Ag+ system, allowing for the suggestion that the TMPD|TMPD+ system may be more suitable than the Ag|Ag+ system as a redox couple for use in reference electrodes for ionic liquids. © 2007 American Chemical Society. |
| spellingShingle | Rogers, E Silvester, D Jones, S Aldous, L Hardacre, C Russell, A Davies, S Compton, R Electrochemical Kinetics of Ag/Ag+ and TMPD|TMPD+. in the Room-Temperature Ionic Liquid [C4mpyrr][NTf2]; toward Optimizing Reference Electrodes for Voltammetry in RTILs |
| title | Electrochemical Kinetics of Ag/Ag+ and TMPD|TMPD+. in the Room-Temperature Ionic Liquid [C4mpyrr][NTf2]; toward Optimizing Reference Electrodes for Voltammetry in RTILs |
| title_full | Electrochemical Kinetics of Ag/Ag+ and TMPD|TMPD+. in the Room-Temperature Ionic Liquid [C4mpyrr][NTf2]; toward Optimizing Reference Electrodes for Voltammetry in RTILs |
| title_fullStr | Electrochemical Kinetics of Ag/Ag+ and TMPD|TMPD+. in the Room-Temperature Ionic Liquid [C4mpyrr][NTf2]; toward Optimizing Reference Electrodes for Voltammetry in RTILs |
| title_full_unstemmed | Electrochemical Kinetics of Ag/Ag+ and TMPD|TMPD+. in the Room-Temperature Ionic Liquid [C4mpyrr][NTf2]; toward Optimizing Reference Electrodes for Voltammetry in RTILs |
| title_short | Electrochemical Kinetics of Ag/Ag+ and TMPD|TMPD+. in the Room-Temperature Ionic Liquid [C4mpyrr][NTf2]; toward Optimizing Reference Electrodes for Voltammetry in RTILs |
| title_sort | electrochemical kinetics of ag ag and tmpd tmpd in the room temperature ionic liquid c4mpyrr ntf2 toward optimizing reference electrodes for voltammetry in rtils |
| work_keys_str_mv | AT rogerse electrochemicalkineticsofagagandtmpdtmpdintheroomtemperatureionicliquidc4mpyrrntf2towardoptimizingreferenceelectrodesforvoltammetryinrtils AT silvesterd electrochemicalkineticsofagagandtmpdtmpdintheroomtemperatureionicliquidc4mpyrrntf2towardoptimizingreferenceelectrodesforvoltammetryinrtils AT joness electrochemicalkineticsofagagandtmpdtmpdintheroomtemperatureionicliquidc4mpyrrntf2towardoptimizingreferenceelectrodesforvoltammetryinrtils AT aldousl electrochemicalkineticsofagagandtmpdtmpdintheroomtemperatureionicliquidc4mpyrrntf2towardoptimizingreferenceelectrodesforvoltammetryinrtils AT hardacrec electrochemicalkineticsofagagandtmpdtmpdintheroomtemperatureionicliquidc4mpyrrntf2towardoptimizingreferenceelectrodesforvoltammetryinrtils AT russella electrochemicalkineticsofagagandtmpdtmpdintheroomtemperatureionicliquidc4mpyrrntf2towardoptimizingreferenceelectrodesforvoltammetryinrtils AT daviess electrochemicalkineticsofagagandtmpdtmpdintheroomtemperatureionicliquidc4mpyrrntf2towardoptimizingreferenceelectrodesforvoltammetryinrtils AT comptonr electrochemicalkineticsofagagandtmpdtmpdintheroomtemperatureionicliquidc4mpyrrntf2towardoptimizingreferenceelectrodesforvoltammetryinrtils |