Electrocatalytic oxidation of methanol at platinum electrode modified with Eu–Fe cyanide-bridged binuclear complexes

Abstract The electrocatalytic oxidation of methanol at the platinum electrode modified with Eu–Fe cyanide-bridged binuclear complexes (Eu–Fe film) was investigated for the first time by cyclic voltammetry. Compared with the bare platinum electrode, the results showed that the modified electrode had excellent electrocatalytic activity for the oxidation of methanol; the oxidation peak potential shifted more negatively and the peak current increased about twenty times. The electrooxidation of methanol at the modified electrode with Eu–Fe cyanide-bridged binuclear complexes material exhibited the better tolerance capacity to poison of intermediate species; the peak current was proportional to the concentration of methanol in the range of 0.5–2.0 mol/L ( R 2  = 0.9991, n  = 7), which was a comparatively wider linear range. Moreover, based on the linear relationship between the peak current and the square root of scan rate, electrocatalytic oxidation process of methanol was confirmed to be a diffusion control process. Furthermore, according to the counting of electron transfer number ( n α ) in the rate-limiting step and the slope of linear equation between acidity of electrolyte and the oxidation peak potential ( E p ), the possible mechanism of the electrooxidation of methanol at the modified electrode was primarily discussed.