Are Polyaniline and Polypyrrole Electrocatalysts for Oxygen (O(2)) Reduction to Hydrogen Peroxide (H(2)O(2))?

[Image: see text] In this report, we present results on the electrocatalytic activity of conducting polymers [polyaniline (PANI) and polypyrrole (PPy)] toward the electrochemical oxygen reduction reaction (ORR) to hydrogen peroxide (H(2)O(2)). The electropolymerization of the polymers and electrolysis conditions were optimized for H(2)O(2) production. On flat glassy carbon (GC) electrodes, the faradaic efficiency (FE) for H(2)O(2) production was significantly improved by the polymers. Rotating disc electrode (RDE) studies revealed that this is mainly a result of blocking further H(2)O(2) to the water reduction pathway by the polymers. PPy on carbon paper (CP) significantly increased the molar production of H(2)O(2) by over 250% at an average FE of above 95% compared to bare CP with a FE of 25%. Thus, the polymers are acting as catalysts on the electrode for the ORR, although their catalytic mechanisms differ from other electrocatalysts.