Pt-Ru polymeric electrocatalysts used for the determination of carbon monoxide

Abstract

Different PtRu polyaniline composite catalysts were studied for the electro-oxidation of carbon monoxide (CO) in order to ascertain their response to the changes in CO bulk concentration in acid solutions. The catalyst substrate consisted of polyaniline films with incorporated carbon nanotubes grown over a Ni wire. To build the electrode, PtRu particles were added to the polymeric film by immersion at open circuit from a solution containing Pt(IV) and Ru(III). The concentration relationship R = [Pt(IV)]/[Ru(III)] was established fixing the Pt(IV) concentration and varying Ru(III) concentration in order to have 0.5 < R < 5. CO electro-oxidation in acid media was studied applying cyclic voltammetry and chronoamperometry, carefully controlling the amount of CO that flowed into the cell. A linear relationship was established between the CO oxidation current density and its concentration in solution for the catalyst prepared with lower R.