Oxidation of methanol on perovskite-type La2-xSrxNiO4 (0 ≤ x ≤ 1) film electrodes modified by dispersed nickel in 1 M KOH

Finely-dispersed nickel particles are electrodeposited on high surface-area perovskite-type La_2-xSr_xNiO₄ (0 ≤ x ≤ 1) electrodes for possible use in a direct methanol fuel cell (DMFC). The study is conducted by cyclic voltammetry, chronoamperometry, impedance spectroscopy and anodic Tafel polarization techniques. The results show that the apparent electrocatalytic activities of the modified oxide electrodes are much higher than those of unmodified electrodes under similar experimental conditions; the observed activity is the greatest with the modified La_1.5Sr_0.5NiO₄ electrode. At 0.550 V (vs. Hg|HgO) in 1 M KOH + 1 M CH₃OH at 25 °C, the latter electrode delivers a current density of over 200 mA cm⁻², whereas other electrodes of the series produce relatively low values (65–117 mA cm⁻²). To our knowledge, such high methanol oxidation current densities have not been reported on any other non-platinum electrode in alkaline solution. Further, the modified electrodes are not poisoned by methanol oxidation intermediates/products.