Methanol electrooxidation on platinum microparticles electrodeposited on poly ( o-methoxyaniline) films

Abstract

In this paper we have studied the electrooxidation of methanol on electrodes obtained through the electrodeposition of platinum microparticles on poly ( o-methoxyaniline) films. The dependence of the electroactivity on the electrodes preparation parameters has been detailed. It has been shown that the concentration of the monomer during the formation of the polymeric films influences the rate of polymer growth and the electrocatalytic activity. A maximum methanol electrooxidation peak current has been observed for polymers grown to an anodic voltammetric charge of approximately 75 mC cm −2. It has been observed that the electroactivity increases when the platinum deposition is carried out in several steps instead of a single potential electrolysis. The conditions that favour a slower deposition process, i.e., smaller H 2PtCl 6 concentrations and smaller electrodeposition overpotential, lead to an enhancement of the methanol electrooxidation currents. This enhancement is attributed to an increase in the platinum surface area as a consequence of a decrease in the platinum particle size.