Accurate Assessment of the Oxygen Reduction Electrocatalytic Activity of Mn/Polypyrrole Nanocomposites Based on Rotating Disk Electrode Measurements, Complemented with Multitechnique Structural Characterizations

Figure 1

(a) Scheme of the electrochemical cell used for the ORR RDE experiment. (b) Macrograph of the poly-Pt electrode used for benchmark tests. (c) Representative flow lines on the electrode surface under rotation. WE, RE, and CE indicate working, reference, and counter electrodes, respectively. (d) Sketch of the catalyst-electrolyte interface depicting the linear O₂ diffusion model that is incorporated in the K–L equation. The dotted line represents the O₂ concentration distribution both in bulk electrolyte (black) and in the boundary layer (yellow). is the boundary layer thickness; and are the O₂ concentrations in the bulk and at the solution catalyst surface, respectively; is the O₂ diffusion-limiting current.