Are Polyaniline and Polypyrrole Electrocatalysts for Oxygen (O2) Reduction to Hydrogen Peroxide (H2O2)?
journal contributionposted on 21.10.2020, 23:14 authored by Hannah Rabl, Dominik Wielend, Serpil Tekoglu, Hathaichanok Seelajaroen, Helmut Neugebauer, Nikolas Heitzmann, Dogukan Hazar Apaydin, Markus Clark Scharber, Niyazi Serdar Sariciftci
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 (H2O2). The electropolymerization of the polymers and electrolysis conditions were optimized for H2O2 production. On flat glassy carbon (GC) electrodes, the faradaic efficiency (FE) for H2O2 production was significantly improved by the polymers. Rotating disc electrode (RDE) studies revealed that this is mainly a result of blocking further H2O2 to the water reduction pathway by the polymers. PPy on carbon paper (CP) significantly increased the molar production of H2O2 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.