Ionophore-Assisted Electrochemistry of Neutral Molecules: Oxidation of Hydrogen in an Ionic Liquid Electrolyte

The electrochemical properties of gas molecules are of high interest for both fundamental and applied research. In this study, we introduce a novel concept to systematically alter the electrochemical behavior and, in particular, the redox potential of neutral gas molecules. The concept is based on the use of an ionophore to bind and stabilize the ionic electrochemical reaction product. We demonstrate that the ionophore-assisted electrochemical oxidation of hydrogen in a room temperature ionic liquid electrolyte is shifted by almost 1 V towards more negative potentials in comparison to an ionophore-free electrolyte. The altered electrochemical response in the presence of the ionophore yields insights into the reaction mechanism and can be used to determine the diffusion coefficient of the ionophore species. The ionophore-modulated electrochemistry of neutral gas molecules opens new avenues for the development of selective electrochemical sensors with reduced cross-sensitivity.