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The electrodeposition of 13-PbO2 from HC104 solutions of Pb(II) at an Au rotated disk electrode (RDE) was studied as a function of applied potential, rotational velocity, and the concentrations of HC104 and Pb(II). A long induction period (i.e., i = 0) is associated with high acidity, low concentration of Pb(II), and high rotational velocity. Following the induction period, the current rises to a steady-state value which is significantly lower than the mass transport-limited value for Pb(II). The steady-state value of electrode current decreases as rotational velocity is increased, contrary to expectations for a mass transport-controlled process at a RDE. The generation of a soluble intermediate species is proposed to account for these observations. Repeated cycles of deposition and stripping of PbO2 at the Au RDE results in a decreasing induction period for subsequent PbO2 deposition. This is concluded to result because a Pb(II) ad-layer (possibly PbO) is formed which is stabilized by interaction with the Au substrate and is not dissolved following the negative potential scan to 0.3V. The original state of the clean Au surface is regenerated by cathodic He(g) evolution, chemical stripping with H202 or KMnO4, or by mechanical abrasion.) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 155.97.178.73 Downloaded on 2014-11-26 to IP