Standard exchange current density

Unfortunately there are numerous examples in the literature where conversion of values of jo obtained at various concentrations did not result in the same value of the standard exchange current density 700 83Kaw]). 

Because of the outlined difficulties in a simple transformation of the exchange current density jo into the standard exchange current density Joo or the rate constant k all values arc listed as reported in the original literature. The exchange current density is usually reported in units of A cm, the rate constant in units of cm s Sometimes the exchange current density or the standard exchange current density are reported in units of A cm mol All values reported below refer to the units outlined initially referring to... 

If no concentration of the educt is given the standard exchange current density y oo is stated. Values of)t are printed in italics values of the apparent rate constant k pp are printed in parentheses in italics. For electrode potentials where the latter rate constant was actually determined the reader is referred to the original literature. 

If no concentration of the educt is given the standard exchange current density y oo is stated. Values of are printed in italics. 

Table 6.2 Estimates of Apparent Standard Exchange Current Densities /q Exchange Current Ratios i o, i/o,K and Selectivity Coefficients Obtained by Different Methods ...

Fig. 24 Experimental volcano plot of the standard exchange current density, logJOi versus M —H bond energy on different metals. (Reprinted with permission from Ref. 55, Copyright 2000 by Elsevier Science).

Here, tit is the number of electrons that are transferred in the rate-determining reaction step. At a Pt PFSI interface nt = 1 has been identified [99,110]. The standard exchange current density (in A cm-2)... 

For a specific reaction, a standard exchange current density can be defined by jOO. j jjjqj l-1 Values of span a range of many orders of magnitude for... 

Experimental Values of Exchange Current Density, Standard Exchange Current Density and Symmetry Coefficient... 

The standard exchange current density (y" ) is defined as the exchange current density when molar concentrations of both Ox (Cqx) and Red (CReactivity coefficients is completely ignored in using Equation 6.9 but could be a problem if high concentrated solutions are considered. The derivation of Equation 6.9 can be found in the literature [2,4],... 

The following section contains information relative to the study of electrode reactions in some nonaqueous single solvents. The organization is alphabetical by solvent and within each table alphabetical by electrolyte. The information includes techniques used, temperature, supporting electrolyte, cathodic and anodic transfer coefficients, standard rate constants, diffusion coefficients and standard exchange current densities. 

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