Circumventing the Sabatier Principle in Electrocatalysis: the Case of Oxygen Reduction Reaction on Au(100) in Alkaline Medium

The barriers for elementary steps in the oxygen reduction reaction (ORR) catalyzed on Au(100) in alkaline solution are mapped out by ab initio molecular dynamics simulations. Due to the relatively weak binding energy of O2 and oxygenated species, the calculated O−O dissociation barrier at ~0.5 eV is indeed considerably higher than the association barrier (< 0.1 eV) to form adsorbed HOO*, pushing ORR towards the thermodynamically less favorable 2e− pathway. However, the kinetics is changed above the equilibrium potential for the association channel ~0.7 V (RHE) where the 2e− pathway is switc... Mehr ...