Hydrogen Evolution, Oxygen Evolution, and Oxygen Reduction at Polarizable Liquid|Liquid Interfaces

Research on hydrogen evolution (HER), oxygen evolution (OER), and oxygen reduction (ORR) reactions at polarizable liquid|liquid interfaces was reviewed. A number of biphasic systems based on hydrophobic molecular solvents and hydrophobic ionic liquids was proposed to carry out these reactions. For HER and ORR metallocenes were extensively explored as electron donors and metallocene hydrides were found as intermediate product. The number of approaches to increase the efficiency of these reactions was proposed. They include assembly/electrodeposition of nanocatalysts at liquid|liquid interface, dissolution of molecular catalysts in organic phase, electro/photochemical regeneration of electron donor, and application of light. For biphasic OER light-driven systems employing nanoparticles assembled at a liquid|liquid interface were reported.