ROTATING HEMISPHERICAL ELECTRODE - ACCURATE EXPRESSIONS FOR THE LIMITING CURRENT AND THE CONVECTIVE WARBURG IMPEDANCE

Citation
Oe. Barcia et al., ROTATING HEMISPHERICAL ELECTRODE - ACCURATE EXPRESSIONS FOR THE LIMITING CURRENT AND THE CONVECTIVE WARBURG IMPEDANCE, Journal of the Electrochemical Society, 145(12), 1998, pp. 4189-4195
Citations number
23
Categorie Soggetti
Electrochemistry,"Materials Science, Coatings & Films
ISSN journal
00134651
Volume
145
Issue
12
Year of publication
1998
Pages
4189 - 4195
Database
ISI
SICI code
0013-4651(1998)145:12<4189:RHE-AE>2.0.ZU;2-T
Abstract
The laminar boundary layer equations describing the steady-state axisy mmetric fluid motion near a spherical surface are solved numerically b y considering a series expansion of the colatitude theta limited to te n terms for each velocity component. The velocity expansions are used in the steady-state mass balance equation to obtain concentration as a series expansion of theta with ten terms. This calculation also provi des the Schmidt number correction to the steady-state current density. Finally, the unsteady state mass balance equation is solved to obtain the convective Warburg impedance of an hemispherical electrode, takin g into account the Schmidt number correction. The impedance results ar e experimentally confirmed over a wide range of dimensionless frequenc y (6 x 10(-3) less than or equal to p less than or equal to 1).