Different interesting enhanced influence from polyaniline and poly(o-toluidine) on electrocatalytic activities of Pt on them toward electrooxidation of methanol

Abstract

Polyaniline (PANI) and poly(o-toluidine) (POT) with various film thickness were electropolymerized using potentiostatic method at the surface of GC electrode. The two conducting polymers were characterized by CV, in situ UV–vis spectroscopy and electrochemical impedance spectroscopy. Two composite catalysts (Pt/PANI/GC and Pt/POT/GC) with various film growth charge have been fabricated by the electro deposition of Pt on the PANI/GC and POT/GC at −0.1 V. then they were used for the electrooxidation of methanol in 0.5 M H2SO4 containing 1.0 M methanol. The properties of both the polymers change with the increase of film growth charge. As-formed composite catalysts were characterized by SEM and the electrochemical methods. The Pt nanoparticles deposited at −0.1 V exhibit thorns morphology and good dispersion on the POT with the film growth charge of 4.5 mC. The electrocatalytic activity for methanol oxidation of Pt/POT/GC is higher than Pt/PANI/GC for all the film charge, and they both exhibit the largest electrocatalytic activity at film charge of 4.5 mC. The present study shows that Pt/POT/GC would be a promising choice for methanol electrooxidation in comparison with Pt/PANI/GC.