Surface addition of Ag on PbO2 to enable efficient oxygen evolution reaction in pH-neutral media

Electrocatalysts, particularly earth-abundant metal oxide ones, exhibit poor performance in catalyzing the oxygen evolution reaction (OER) under neutral conditions due to low ionic concentrations. This study introduces a novel strategy for fabricating a PbO2 + Ag composite electrode with significantly improved OER activity and stability in a pH-neutral environment. Our results suggest that incorporating Ag as a surface additive improves the efficiency of utilizing adsorbed oxygenated species via the bridge-site-top-site pathway. Moreover, the surface decoration of Ag resulted in enhanced electrocatalytic stability by diverting the attack of oxygenated species to Pb thereby effectively preventing Pb dissolution. The results not only establish a method for utilizing PbO2 in pH-neutral OER applications, but also propose a potential strategy for employing less noble catalysts in cost-effective electrochemical energy conversions.