Pt-Co alloy nanoparticles synthesized on sulfur-modified carbon nanotubes as electrocatalysts for methanol electrooxidation reaction

► Pt-Co/CNT nanoparticles were synthesized on sulfur-modified CNTs. ► The modified support prevents agglomeration of nanoparticles during annealing at high temperature. ► The particle size was ∼3 nm; enlargement was insignificant on annealing up to 800 °C. ► The method affords alloyed cubo-octahedral nanocrystals with high stability. ► Pt3Co/CNT was the most active catalyst for methanol oxidation reaction.