Theory of Square-Wave Voltammetry of Two-Electron Reduction with the Adsorption of Intermediate

Table 1

Meanings of symbols.

𝛽	Adsorption constant
𝑐Ox, 𝑐Int, 𝑐Red	Concentrations of the reactant, intermediate and the product
𝑐^∗Ox	Concentrations of the reactant in the bulk of solution
D	Common diffusion coefficient
dE	Square-wave potential increment
E	Electrode potential
𝐸^01, 𝐸^02	Standard potentials of the first and the second electron transfers
𝐸sw	Square-wave amplitude
𝐸𝑝	Peak potential
𝐸𝑝,1,𝐸𝑝,2	Peak potentials of the prepeak and postpeak
𝐸𝑝,𝑓,𝐸𝑝,𝑏	Peak potentials of the forward and backward components
𝐸st	Starting potential
F	Faraday constant
f	Square-wave frequency
φ	Dimensionless potential difference
Φ	Dimensionless current
Φ𝑓,Φ𝑏	Dimensionless currents of the forward and backward components
−ΔΦ𝑝	Dimensionless net peak current
Φ𝑝,𝑓,Φ𝑝,𝑏	Dimensionless peak currents of the forward and back wardcomponents
ΓInt	Surface concentration of adsorbed intermediate
Γmax	Maximum surface concentration of adsorbed intermediate
R	Gas constant
S	Electrode surface area
t	Time
T	Temperature
𝜃	Surface coverage
x	Distance perpendicular to the electrode surface