Enhanced Methanol Electro-Oxidation Activity of Nanoclustered Gold

Size-selected 3 nm gas-phase Au clusters dispersed by cluster beam deposition (CBD) on a conducting fluorine-doped tin oxide template show strong enhancement in mass activity for the methanol electro-oxidation (MEO) reaction compared to previously reported nanostructured gold electrodes. Density functional theory-based modeling on the corresponding Au clusters guided by experiments attributes this high MEO activity to the high density of exposed under-coordinated Au atoms at their faceted surface. In the description of the activity trends, vertices and edges are the most active sites due to their favorable CO and OH adsorption energies. The faceted structures occurring in this size range, partly preserved upon deposition, may also prevent destructive restructuring during the oxidation-reduction cycle. These results highlight the benefits of using CBD in fine-tuning material properties on the nanoscale and designing high-performance fuel cell electrodes with less material usage.

Automated summary

Size-selected 3 nm gas-phase Au clusters deposited via cluster beam deposition on a conducting fluorine-doped tin oxide template exhibit a strong enhancement in mass activity for the methanol electro-oxidation reaction compared to previously reported nanostructured gold electrodes. The high MEO activity is attributed to the high density of exposed under-coordinated Au atoms on their faceted surface, with vertices and edges being the most active sites due to their favorable CO and OH adsorption energies. The faceted structures in this size range, partly retained during deposition, may also protect against destructive restructuring during the oxidation-reduction cycle.