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Title: Concentration and density changes at an electrode surface and the principle of unchanging total concentration

Journal Article · · Journal of the Electrochemical Society
DOI:https://doi.org/10.1149/2.0231604jes· OSTI ID:1240714
 [1]
  1. Brookhaven National Lab. (BNL), Upton, NY (United States)

In this study, the principle of unchanging total concentration as described by Oldham and Feldberg [J. Phys. Chem. B, 103, 1699 (1999)] is invoked to analyze systems comprising a redox pair (Xz11 and Xz22) plus one or more non-electroactive species (Xz33,Xz44...Xzjmaxjmax) where Xzjj is the jth species with charge zj and concentration; cj. The principle states that if the diffusion coefficients for all species are identical and mass transport is governed by the Nernst-Planck expression, the total concentration does not change during any electrochemical perturbation, i.e.: Σjmaxj=1[Xzjj]=Σjmaxj=1 cj = SP With this principle we deduce the electrochemically induced difference between the surface and bulk concentrations for each species. Those concentration differences are translated into density differences which are a function of the density of the solvent and of the concentration differences, molecular masses and the standard partial molar volumes of all species. Those density differences in turn can induce convection that will ultimately modify the observed current. However, we did not attempt to quantify details of the natural convection and current modification produced by those density differences.

Research Organization:
Brookhaven National Lab. (BNL), Upton, NY (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Biological and Environmental Research (BER)
Grant/Contract Number:
SC00112704
OSTI ID:
1240714
Report Number(s):
BNL-111892-2016-JA; R&D Project: 2016-BNL-EE630EECA-Budg; KP1701000
Journal Information:
Journal of the Electrochemical Society, Vol. 163, Issue 4; ISSN 0013-4651
Publisher:
The Electrochemical SocietyCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 2 works
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