Chemistry
How Proton-Coupled Electron Transfer Enables Oxygen Reduction in Fuel Cells
Quick fact
In fuel cell cathodes, oxygen reduction is slow mainly because it requires four coupled proton and electron transfers; bypassing this coupling to generate hydrogen peroxide instead would release far less energy and damage the fuel cell.
Why this is interesting
You know a fuel cell turns hydrogen and oxygen into electricity and water. But have you ever wondered how a single oxygen molecule gets reduced to water without blowing up the cell?