Methanol oxidation on the polymer coated and polymer-stabilized Pt nano-particles: A comparative study of permeability and catalyst particle distribution ability of the PANI and its derivatives

The electrosynthesis and characterization of poly (aniline and aniline derivatives) on the pretreated aluminum (Al/Pt) and platinum plated aluminum (Al–Pt) electrodes were investigated. The results show that the both of them are suitable substrates as well as smooth Pt and platinum plated Pt (Pt–Pt) for fabrication of polymer modified electrodes. Comparative study of permeability of the freshly deposited polyaniline and polyaniline derivatives on the smooth Pt and Al–Pt or Pt–Pt substrates towards the methanol were done. The electrooxidation of methanol was studied by cyclic voltammetry in 0.1 M sulfuric acid as supporting electrolyte. Enhanced electrocatalytic activity towards the methanol oxidation was noticed when the bulk Pt and Al–Pt or Pt–Pt were covered by polyaminoanilines and polyhydroxyanilines films due to the permeability of their films for methanol molecules. A high catalytic current related to oxidation of methanol was found for the polymer modified electrodes when Pt nano-particles were embedded into the polymer films referred to as polymers-stabilized Pt nano-particles. The enhanced electrocatalytic activity might be due to the dispersion of Pt nano-particles into the polymer matrixes and the synergistic effects between the dispersed Pt particles and their matrixes.