Carbon monoxide and methanol oxidation on potential-modified Pt-Ru/C electrocatalyst for polymer electrolyte fuel cells

► The anodic treatment of Pt-Ru/C catalysts activate CO and methanol electrooxidation. ► The beneficial RuOxHy is optimally produced in the potential range 1.4-1.6 V. ► The anodic treatment at 1.8 V is not suitable because RuOxHy is lost into solution. ► The ECSA for CO stripping is reduced due to the RuOxHy formation. ► The surface analyses show the presence of crystalline and amorphous oxides.