Publications

Manganese oxide/poly(3,4-ethylenedioxythiophene) hybrid electrocatalysts for the oxygen reduction reaction in alkaline fuel cells

Lambert, Timothy N.; Vigil, Julian A.

Manganese oxide/poly(3,4-ethylene-dioxythiophene) (MnO_x/ PEDOT) nanostructured hybrid thin films were prepared using a simple anodic electrodeposition process from aqueous solution, and then tested for oxygen reduction reaction (ORR) activity in alkaline electrolyte using rotating disk electrode and rotating ring disk electrode methods. MnO_x/PEDOT provided improvements over MnO_x-only and PEDOT-only control films, with > 0.2 V decrease in onset and half-wave overpotentials, and > 1.5 times increase in terminal current density. The MnO_x/PEDOT film exhibited only a slightly lower n value (n = 3.86-3.92) than the 20% Pt/C benchmark electrocatalyst (n = 3.98) across all potentials. MnO_x/PEDOT also displayed a more positive half-wave potential and superior electrocatalytic selectivity for the ORR upon methanol exposure than 20% Pt/C. Here, the high activity and synergism of MnO_x/PEDOT towards the ORR is attributed to effective intermixing/dispersion of the two materials, intimate substrate contact with improved charge transfer processes attained by co-electrodepositing MnO_x with PEDOT and due to the increase in Mn³⁺ content at the surface of the oxide.