Electrocatalytic properties and electrochemical stability of polyaniline and polyaniline modified with platinum nanoparticles in formaldehyde medium

We report the electro-oxidation of formaldehyde on polyaniline films modified with Pt nanoparticles (PANI-Pt films) in an aqueous sulfuric acid solution. The electrodeposition of Pt particles on the PANI matrix was found to promote a mass loss of the film, with a similar effect occurring after cycling the PANI films in the acidic medium containing formaldehyde. However, despite the electrochemical instability of PANI-Pt films, on films containing larger amounts of incorporated Pt particles, the oxidation of formaldehyde produces adsorbed CO species (CO_ads) at a lower positive potential than on bulk Pt. Our findings also indicate that electro-oxidation of CO_ads on the PANI-Pt film surface depends not only on the thickness of PANI film but also on the amount of Pt particles incorporated into the PANI matrix.