The electrochemical behaviour of protic quaternary amine based room-temperature ionic liquid N2210(OTf) at negatively and positively polarized micro-mesoporous carbon electrode investigated by in situ X-ray photoelectron spectroscopy, in situ mass-spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy methods

Abstract

The electrochemical behaviour of a protic quaternary amine cation based room-temperature ionic liquid (RTIL), diethylmethylammonium trifluoromethanesulfonate [N2210(OTf)], has been investigated at negatively and positively polarized molybdenum carbide derived micro-mesoporous carbon [mmp-C(Mo2C)] electrodes by in situ X-ray photoelectron spectroscopy (XPS), in situ mass-spectroscopy (MS), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods. Collected data indicate that N2210(OTf) adsorbs strongly at E ≤ −1.10 V (vs. Ag-QRE) at the mmp-C(Mo2C) electrode. Intensive electroreduction of N2210+ cation took place at E ≤ −1.20 V (vs. Ag-QRE) producing various organic gases, instead of hydrogen, detected in situ by a restgas analyser. At E > 1.50 V (vs. Ag-QRE), remarkable passivation of the mmp-C(Mo2C) electrode took place. C 1 s, O 1 s, F 1 s and S 2p photoelectron signals became slightly distorted at E = 1.50 V (vs. Ag-QRE) indicating the formation of a surface film at mmp-C(Mo2C) involving triflate anion decomposition products.