The fraction of the neutral and electron polaron states of the polymer as a function of applied voltage are determined using Butler-Volmer kinetics and the steady state approximation. The steady state solutions are simultaneously fit to both the experimental log current densityvoltage (or Tafel) data and the linear disk current density-voltage RRDE data at all pH's to extract a self-consistent set of fitting parameters describing the thermodynamics and kinetics of each elementary reaction step. The pH-independent fitting parameters are the formal reduction voltage of reaction [7]: 𝐸 1 0′ ; and the associated chemical and electrochemical reaction rate constants and symmetry coefficients: 𝑘 1 0 , 𝛽 1 , 𝑘 𝑓,2 . The 𝑘 𝑓,3 parameter is treated as pHdependent, and each experimental pH has its own 𝑘 𝑓,3 fit. Note that the equilibrium constant for reaction [8], 𝐾 2 , is defined through