PtCu catalyst for the electro-oxidation of ethanol in an alkaline direct alcohol fuel cell

A PtCu electrocatalyst was synthesized using a galvanic displacement route obtaining nanoparticles with a semi-spherical morphology and an average size of 4 nm, supported on carbon black (Vulcan). The crystallographic characterization by X-ray diffraction showed a certain degree of Pt-Cu alloying. The electrocatalytic activity of the prepared electrocatalyst for the electro-oxidation of ethanol in alkaline media was investigated. A 2-fold increase of the peak current density and a negative shift of the potential were recorded in half-cell experiments for the bimetallic catalyst compared to a commercial Pt/C. The presence of Cu promotes ethanol oxidation in alkaline electrolyte by hindering the Pt-H adsorption at low overpotentials. Additionally, the PtCu electrocatalyst was used as anode in an anion-exchange-membrane direct ethanol fuel cell (AEM-DEFC) exhibiting about 2-fold higher power density than the benchmark Pt/C.