Electrocatalysis at the polarised interface between two immiscible electrolyte solutions

Electrocatalysis at the interface between two immiscible electrolyte solutions (ITIES) is an emerging field of research, which allows the separation of reactants according to their lipophilicity. Electrocatalysts of various nature (noble metals, carbon-based and inorganic nanomaterials, enzymes and supramolecular ensembles) are assembled at the ITIES, either spontaneously or following the application of an interfacial Galvani potential difference. While primarily used for the electrocatalysis of the oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER), recent work has focused on the electrocatalysis of the oxygen evolution reaction (OER) and the electrocatalytic oxidation of elemental sulfur (S₈) and an organosulfur compound. Protocols to compare electrocatalytic performances at the ITIES call for careful data analysis and a detailed knowledge of the catalysts morphological parameters (e.g., active surface area and catalyst loading). However, standardisation of such protocols at the ITIES has yet to be implemented and is required to allow better comparison of the results from individual biphasic systems.