A Novel Approach for Differential Electrochemical Mass Spectrometry Studies on the Decomposition of Ionic Liquids

Effect of Li+ and Mg2+ on the Electrochemical Decomposition of the Ionic Liquid 1‐Butyl‐1‐ methylpyrrolidinium bis(trifluoromethanesulfonyl)imide and Related Electrolytes

“…Based on the comparison, the ion currents measured between −1.0 and −2.6 V seem to be due to the reduction of impurities in the Merck IL rather than to an inherent slow decomposition of the IL in this potential range. This conclusion differs from our previous assignment, where we had tentatively favored an initial reduction of the BMP + cation via the scission of the bond between the pyrrolidinium ring and the butyl chain along reaction path R2, since we had made the same observations in two different batches of BMP‐TFSI …”

“…The small difference of 0.04 V between the peak positions for the two ILs, may be due to (different) impurities in the two ILs. Another possible reason is the variation in the potential of the quasi‐reference electrode, which turned out to be around ±0.1 V in repeated measurements with Fc/Fc + . At more cathodic potentials, in the Merck electrolyte the exponential increase of the cathodic current starts at −2.4 V, which is about 0.2 V more positive in comparison to the red (Solvionic) curve.…”

NMR Study of the Reductive Decomposition of [BMIm][NTf2] at Gold Electrodes and Indirect Electrochemical Conversion of CO2

“…The cathodic stability of the NTf 2 À anion remains as ubject of debate [29] and was therefore also investigated in the present study.A si llustrated in the Supporting Information,n oa lterationo ft he ionic liquid was detectedb y 19 FNMR, suggesting that the NTf 2 À anion is not reductively decomposed at À2.5 Vv s. Fc + /Fc and does not react with the conversion products of the BMIm + cation. The cathodic stability of the NTf 2 À anion remains as ubject of debate [29] and was therefore also investigated in the present study.A si llustrated in the Supporting Information,n oa lterationo ft he ionic liquid was detectedb y 19 FNMR, suggesting that the NTf 2 À anion is not reductively decomposed at À2.5 Vv s. Fc + /Fc and does not react with the conversion products of the BMIm + cation.…”

“…[8] The electrochemical stability of am ediumc an be evaluated by the width of its electrochemical potential window.F or imidazolium-based ionic liquids, it is typicallyl imited by the reduction of the cation and the oxidation of the anion. [10,16,17] Several studies report on the electrochemical stability of ionic liquids [15,[18][19][20][21][22][23][24][25][26][27][28][29][30][31] and especially neat imidazolium-based ionic liquids [15,21,[23][24][25] at very negative potentials. [10,16,17] Several studies report on the electrochemical stability of ionic liquids [15,[18][19][20][21][22][23][24][25][26][27][28][29][30][31] and especially neat imidazolium-based ionic liquids [15,21,[23][24][25] at very negative po...…”

“…[1,2,[9][10][11][12][13][14][15][16] It depends of course on the ionic species [1,2,10,12,13,16] but also on the material of the working electrode [2,[10][11][12][13][14] and on the presence of impuritiesincluding water. They mainly rely on quantum chemical calculations [15,21] or experimental investigations by NMR, [21,24,25,32] mass spectrometry [24,25,29] or in situ infrared spectroscopy. They mainly rely on quantum chemical calculations [15,21] or experimental investigations by NMR, [21,24,25,32] mass spectrometry [24,25,29] or in situ infrared spectroscopy.…”