Main-Group Potassium-Assisted Dual-Site Relay Breaks the Activity-Stability Trade-Off in Acidic Oxygen Reduction.
Fe-N-C catalysts are promising platinum-group-metal-free cathodes for proton-exchange membrane fuel cells. However, O2 activation on isolated FeN4 sites typically follows a single-center associative pathway, which limits (oxygen reduction reaction) ORR kinetics and is associated with peroxide formation and Fe demetalat...