Stable Tetrasubstituted Quinone Redox Reservoir for Enhancing Decoupled Hydrogen and Oxygen Evolution

in a continuous flow electrolysis cell. The reduced RR, tetramercaptopropanesulfonate hydroquinone (TMHQ), is not susceptible to decomposition, while the oxidized state, TMQ, undergoes slow decomposition, evident only after sustained operation (>60 h). Analysis of the byproducts provides that basis for a decomposition mechanism, establishing a foundation for the design of new organic RRs with even better performance.