Systematic approach to the quantitative voltammetric analysis of the Fe(super III)/Fe(super II) component of the [alpha(sub 2)-Fe(OH(sub 2))P(sub 2)W(sub 17)O(sub 61)](super 7-/8-) reduction process in buffered and unbuffered aqueous media

The one-electron reduction of [alpha(sub 2)-Fe(OH(sub 2))P(sub 2)W(sub 17)O(sub 61)](super 7-) at a glassy carbon electrode was investigated using cyclic and rotating-disk-electrode voltammetry in buffered and unbuffered aqueous solutions over the pH range 3.45-7.50 with an ionic strength of approximately 0.6 M maintained. Analysis of the simulations illustrates the contribution of the buffer in terms of general acid-base catalysis, a pathway not available in unbuffered media.