Polyaniline (PANI) can be doped with poly(styrene sulfonic acid) (PSS) via doping-dedoping-redoping process. The specific characteristics of PANI doped with PSS (PANI-PSS) were checked by UV-vis spectroscopy, cyclic voltammetry, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). PANI-PSS was found to have spatial structure with minimum degradation products. Platinum can be potentiostatically deposited in a spatial layer of the PANI-PSS as evidenced by electron dispersive element analysis (EDS) and Auger electron spectroscopy (AES). The electrochemical measurements demonstrated that PANI-PSS-Pt exhibited a much higher electrocatalytic activity for methanol oxidation than PANI-Pt. (c) 2006 Elsevier B.V. All rights reserved.