In situ electrochemical XPS study of the Pt/[EMIM][BF4] system

In situ XPS analysis of the electrochemical system [EMIM][BF4]/Pt was performed in a three electrode electrochemical cell as a function of electrode potential. The so-called electrochemical shift of the binding energy of electrolyte species with the applied electrode potential is confirmed. The reductive degradation of [EMIM][BF4] at a potential of − 1.9 V vs. a carbon quasi reference electrode is demonstrated.

Research Highlights► In situ XPS studies in a three-electrode electrochemical cell. ► The electrochemical shift was confirmed to be 1.0 eV/V. ► The N 1s line indicates a degradation product of [EMIM]. ► The degradation product is attributed to species in the electrolyte.