Superior CO-tolerance and stability toward alcohol electro-oxidation reaction of 1D-bimetallic platinum-cobalt nanowires on Tungsten-modified anatase TiO2 nanostructure

Abstract

Direct alcohol fuel cells (DAFCs) use liquid and renewable fuels that have been sparked significant interest in a variety of applications; however, the poor catalytic performance of the state-of-the-art Pt nanoparticles (NPs) over carbon support is a major challenge for further DAFC utilization. Herein, the 1D-bimetallic Pt3Co nanowires with a diameter of ~4 nm and the lengths of up to several tens nanometers were grown firstly on the non-carbon Ti0.7W0.3O2 nanoparticles via a template- and surfactant-free chemical reduction preparation at room temperature. Electrochemical results indicated that the bimetallic Pt3Co NWs/Ti0.7W0.3O2 catalyst was an effective electrocatalyst toward alcohol (methanol, ethanol) electrochemical oxidation. For instance, the bimetallic Pt3Co NWs/Ti0.7W0.3O2 catalyst exhibited high mass activity (MOR of ~393.29 mAmgPt-1and EOR of ~341.76 mAmgPt-1), low onset potential (~0.01 V vs. NHE for MOR and ~0.20 V vs. NHE for EOR) and superior CO-tolerance (If/Ib value for MOR of ~3.11 and EOR of ~1.54) in comparison with the conventional carbon-supported Pt nanoparticles (NPs) catalyst. Additionally, the mass activity loss of the Ti0.7W0.3O2-supported Pt3Co (NWs) catalyst was ~10.68% of the initial mass activity, which ~4.18-time lower than that of the carbon-supported Pt (NPs) catalyst (~44.66% of the initial mass activity) after 5000 cycles test, indicating the superior stability retention of the as-obtained Pt3Co NWs/Ti0.7W0.3O2 electrocatalyst. These enhancements were attributable to the combination of the advantageous 1D nanostructures with the internal effect of the Pt3Co nanowires, the synergistic effect between Pt-M alloy and TiO2-based nanomaterials and the superior anti-corrosion possibility of the non-carbon support.