WO3 decorated carbon nanotube supported PtSn nanoparticles with enhanced activity towards electrochemical oxidation of ethylene glycol in direct alcohol fuel cells

This paper describes the concept of the utilization of metal oxide (WO₃) modified multi-walled carbon nanotubes (MWCNT) for supporting and activating PtSn nanoparticles (PtSn/WO₃-MWCNT and PtSn/MWCNT) for ethylene glycol oxidation. The resulting nanocomposite was developed and characterized using electrochemical and microscopic (TEM, SEM−EDS) techniques, as well as XRD analysis. The electrocatalytic currents measured under voltammetric and chronoamperometric conditions were greater than those found with the commercially available Vulcan-supported Pt₃Sn nanoparticles, which were used as reference catalysts. In situ FTIR spectroscopy was used to detect the formation of oxidation intermediates or products during the ethylene glycol oxidation. Combining the transition metal oxide species with Pt-based nanoparticles can generate OH groups at low potentials. These groups participate in the oxidation of passivating CO adsorbates on the Pt surface, and can also potentially break CH bonds. Further, the effectiveness of synthesized catalyst has been assessed through testing both catalysts in the single fuel cell. A single fuel cell with a PtSn/WO₃-MWCNT anode gave a better performance than one with a pristine PtSn/Vulcan anode, with a current density of around 79.8 mA cm⁻² and an output power density of 20.5 mW cm⁻².