A Bio-Inspired, Small Molecule Electron-Coupled-Proton Buffer for Decoupling the Half-Reactions of Electrolytic Water Splitting

Electron-coupled-proton buffers (ECPBs) allow H-2 and O-2 evolution to be separated from each other in time during the electrolysis of water. Natural photosynthetic systems achieve an analogous feat during water splitting and employ a range of intermediate redox mediators such as quinone derivatives to aid this process. Drawing on this natural example, we show that a low molecular weight quinone derivative is capable of decoupling H-2 evolution from O-2 evolution at scale during electrochemical water splitting. This work could significantly lower the cost of ECPBs, paving the way for their. more widespread adoption in water splitting.