Mixed-reactant ethanol fuel cell using an electrochemically deposited Ag@Pt tolerant cathode

In the present work, we report an ethanol tolerant cathode catalyst developed through a two-stages electrodeposition of Pt and Ag nanoparticles on a glassy carbon electrode using chronoamperometric and voltammetric techniques. The resulting nanoparticles were characterized by Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), X-Ray Photoelectron Spectroscopy (XPS) and electrochemical techniques. According to the SEM study, the synthetized particles have semi-spherical shape and their average diameter is 200 nm. The catalyst showed a layer onto layer or a core-shell-like architecture, where the silver layer that was built onto the platinum surface covers the nanoparticles. This Ag@Pt catalyst was successfully evaluated for the oxygen reduction reaction, involving a four-electron transfer mechanism. Additionally, it exhibited high tolerance to ethanol oxidation reaction. The onset potential of the ORR was 0.81 V in presence of 5 M EtOH. The catalyst was further tested as cathode in an alkaline mixed-reactant fuel cell using 1 M EtOH + O2, yielding more than 400 mV and 20 μW cm−2.