THE ELECTROCATALYTIC OXIDATION OF ASCORBIC-ACID ON PRUSSIAN BLUE FILM MODIFIED ELECTRODES

It is found for the first time that the electro-oxidation of ascorbic acid can be effectively catalyzed by Prussian blue films with a rate constant of 1. 23 multiplied by 10**8 cm**3 mol** minus **1 s** minus **1. The kinetics of the reaction was studied in some detail which demonstrates the applicability of the reaction-layer theory of modified electrodes for electrocatalysis to the inorganic mixed-valent compound film. It is demonstrated that PB film can quickly catalyze the oxidation of AH//2 when it is relatively thin and charge-transport process inside the film will take part in the rate-limiting when it becomes thick. The catalytic behavior of the film favors the reaction-layer theory developed by J. M. Saveant et al.