POTENTIODYNAMIC DETERMINATION OF ELECTRODE KINETICS FOR CHEMISORBED REACTANTS - AG/AG2O/OH-SYSTEM

An examination of current/time (or current/potential) parameters obtained under potentio-dynamic conditions is made for adsorbed reactants where a reverse reaction and diffusion of the products are of no consequence. Particular attention has been paid to the implications of varying reaction orders for the electrode reactions. The equations have been used to examine in detail the formation (second-order) and reduction (first-order) of Ag2O in 1 N NaOH. The silver electrodes were prepared as thin fihns on rhodium substrates to control the mass of reacting silver. The transfer coefficient was determined from experimental results for both formation and reduction of Ag2O to be α = 0·71± 0·03. The formation of AgOH is rapid and is distinguished from the formation of Ag2O so that different values of the standard electrode potential for the Ag/AgOH/OH- and the Ag/Ag2O/OH- couples can be determined. The Ag/AgOH/OH- couple is considered to be the potential-determining reaction for the reversible silver/silver-oxide electrode. © 1968.