Page 51 - Analytical Electrochemistry 2d Ed - Jospeh Wang

36 STUDY OF ELECTRODE REACTIONS

TABLE 2-1 Electrochemical Mechanisms InvolvingCoupled Chemical Reactions
1. Reversible electron transfer, no chemical complications:

O ‡ ne „ R

2. Reversible electron transfer followed by a reversible chemical reaction, E C mechanism:
r
r

O ‡ ne „ R
k t
R ! Z
k 1
3. Reversible electron transfer followed by an irreversible chemical reaction, E C mechanism:
i
r

O ‡ ne „ R
k
R ! Z
4. Reversible chemical reaction preceding a reversible electron transfer, C E mechanism:
r r
k 1
Z ! O
k 1

O ‡ ne „ R
5. Reversible chemical reaction preceding an irreversible electron transfer, C E mechanism:
r i
k 1
Z ! O
k 1
O ‡ ne „ R

6. Reversible electron transfer followed by an irreversible regeneration of starting materials,
catalytic mechanism:
O ‡ ne „ R

k
R ‡ Z ! O
7. Irreversible electron transfer followed by an irreversible regeneration of starting material:

O ‡ ne „ R
k
R ‡ Z ! O
8. Multiple electron transfer with intervening chemical reactionÐECE mechanism
O ‡ n e „ R R „ Y
1
Y ‡ n e „ Z

2
Adapted with permission from reference 88.

been developed (9). Such simulated voltammograms can be compared with and
®tted to the experimental ones. The new software also provides movie-like
presentations of the corresponding continuous changes in the concentration pro®les.

2-1.3 Study of Adsorption Processes
Cyclic voltammetry can also be used for evaluating the interfacial behavior of
electroactive compounds. Both the reactant and the product can be involved in an