Matsuda-Ayabe parameter

The Matsuda-Ayabe parameter. A, quantifies kinetic reversibility for an electrochemical process ... 

At the point of transition between reversible voltammetry and quasi-reversibiUty, A 15. Therefore for the lower two scan rates, we can infer that A > 15. For the faster two scan rates, the behaviour is quasi-reversible so we expect that the Matsuda-Ayabe parameter is < 15. 

The quasireversible LSV case was treated by Matsuda and Ayabe [389], who used a series sum as an approximation to the integral equation obtained from the Laplace-transform solution of the problem. The result depends on the heterogeneous rate constant, both the peak current and the peak potential varying with this parameter. Basha et al. [82] tried to improve on the results but it seems that those of Nicholson and Shain [417] were better. These also provided results for the totally irreversible case, first described by Delahay [199]. For this, the y(ai)-function has a constant maximum, given to four figures in [73,74], 0.4958, from the tables in [417]. Peak potential varies with rate constant, as with the quasireversible case. 

The distinction between fast and slow electrode kinetics relates to the prevailing rate of mass transport given by kf mx indicating electrochemical reversibility or "k electrochemical irreversibility. Matsuda and Ayabe [2] introduce the parameter, given by ... 

---