Synthesis and characterization of Cu core Pt-Ru shell nanoparticles for the electro-oxidation of alcohols

Cu@Pt-Ru core-shell supported electrocatalysts have been synthesized by a two-step process via a galvanic displacement reaction. XRD diffraction and EDX analysis, and cyclic voltammetry measurements revealed the presence of nanoparticles composed by a Cu-rich Pt-Cu core surrounded by a Pt-rich Pt-Ru shell. Cyclic voltammetry and chronoamperometric measurements showed that as-synthesized core-shell materials exhibit superior catalytic activity towards methanol and ethanol electro-oxidation compared to a commercial Pt-Ru/C catalyst with higher Pt loading. This behavior can be associated with the lattice mismatch between the Pt-rich shell and the Cu rich core, which in turn produces lattice-strain, surface ligand effects and a large amount of surface defect sites. In addition, the core-shell electrodes displayed a better catalytic activity and lower onset potentials for ethanol oxidation than for methanol oxidation.