Enhanced Electrocatalytic Activity of Pt-M (M= Co, Fe) Chitosan Supported Catalysts for Ethanol Electrooxidation in Fuel Cells

Abstract

Here, metal nanoparticles were synthesized by chemical reduction of the corresponding metal salts in the presence of chitosan polymer. Binary and ternary metallic-chitosan Pt-Fe-CH, Pt-Co-CH and Pt-Fe-Co-CH nanocomposites were prepared. Transmission electron microscopy images and UV–Vis spectra of the nanocomposites confirmed the presence of the metal nanoparticles. The electrocatalytic activity of the nanocomposites for ethanol oxidation was tested by cyclic voltammetry, Liner Sweep Voltammetry, amperometric i-t curve and electrochemical impedance spectroscopy techniques. The effect of some experimental factors on ethanol oxidation was investigated. CO stripping was used to determine the CO tolerance of the catalysts for ethanol oxidation. Incorporation of small amounts of Co and Fe nanoparticles in the Pt-CH catalyst caused the higher activity of the catalyst for ethanol electrooxidation. The activation energy of Pt-Co-Fe-CH catalyst obtained from the Arrhenius equation was lower than other studied catalysts. These results showed that Pt-Fe-Co-CH catalyst has better catalytic activity for ethanol oxidation among all prepared catalysts.