Study of electrocatalytic properties of platinum-loaded poly-ortho-aminophenol film towards methanol oxidation and hydrogen evolution

Abstract

Platinum microparticles electrodeposited at a glassy carbon surface (Pt/GC) and within a poly-<i>ortho</i>-aminophenol film formed on a GC substrate (Pt/PoAP/GC) have been used for investigating their catalytic activity towards hydrogen evolution reaction and methanol oxidation by cyclic voltammetry, impedance spectroscopy and chronoamperometry. The effect of the deposition time (<i>t</i>_dcp) of the Pt particles dispersed into GC and PoAP electrodes and of the acid anions (SO₄^2-, ClO4ˉ) on the hydrogen adsorption/desorption peaks and hydrogen evolution reaction has been studied. It has been shown that the main cause of immediate blocking of the PoAP-SO₄^2- pores with platinum microparticles is its smaller scaling yardstick. The higher electrocatalytic activity of the PoAP as compared to that of GC due to its higher surface area for the methanol oxidation has been proved by a substantial improvement in transition current in chronoamperometric and in the maximum anodic current of the methanol in cyclic voltammetric measurements.