Methanol, ethanol and ethylene glycol electro-oxidation at Pt and Pt–Ru catalysts electrodeposited over oxidized carbon nanotubes

Pt and Pt–Ru catalysts supported on oxidized multi-walled carbon nanotubes with different ruthenium content ranging from 19 to 30 at.% were prepared by pulse electrodeposition and tested for methanol, ethanol and ethylene glycol oxidation in H2SO4 electrolyte. The catalysts were mainly composed by small 3D irregular-shaped agglomerates of nano-sized particles. ocatalytic activity measurements indicated that the bimetallic catalyst with 30 at.% Ru was the most active electrode for methanol, ethanol and ethylene glycol oxidation. This behavior can be associated with a synergistic effect between the facilitation of alcohol oxidation via oxygen-containing species adsorbed on Ru atoms, the suitable Pt ensemble size and the modification of the electronic structure of Pt atoms at the Fermi level that weakens the adsorption of CO and other intermediates.