We synthesized Pt, Pt–Ru alloy and Pt–Ru–Mo alloy nanoparticles on the multi-walled carbon nanotubes (MWCNTs) using flash light irradiation and characterized these catalysts. Pt100, Pt50-Ru50 alloy and Pt43-Ru43-Mo14 alloy are coated onto MWCNTs followed by flash light irradiation to facilitate the formation of nanoparticle-alloys. The fabricated pure Pt and Pt-based alloy nanoparticle/MWCNTs were characterized by X-ray diffraction (XRD), raman spectroscopy and scanning electron microscopy (SEM). Cyclic voltammetry (CV) studies and electrochemical impedance spectroscopy (EIS) results revealed that the Pt43-Ru43-Mo14/MWCNT catalyst has higher activity and stability with regard to methanol electro-oxidation than the Pt100/MWCNT and Pt50-Ru50/MWCNT catalysts.