Fig. 6.

Electrocatalytic reduction of O₂ in 1 mol L⁻¹ HClO₄ at a rotating graphite disk electrode coated with (PMes₂CO)Co₂ 1. (a) Values of the rotation rates of the electrode (w) are indicated on each curve. The disk potential was scanned at 5 mV s⁻¹. (b) Levich plots of the plateau currents of (a) vs. (rotation rate)^1/2. The dashed line refers to the theoretical curve expected for the diffusion-convection limited reduction of O₂ by 2e⁻. (c) Koutecky-Levich plots of the reciprocal plateau currents vs. (rotation rates)^−1/2. Supporting electrolyte: 1 mol L⁻¹ HClO₄ saturated with air.