In an attempt to find a cost-effective catalyst with high efficiency, a simple method is adopted for the synthesis of colloidal-supported bimetallic nanoparticles (Pt-Mo on silica nanoparticles) as potential catalysts. From UV-vis spectroscopy, the absence of the Pt2+ peak confirmed the formation of Pt nanoparticles. Mo nanoparticles were synthesized using different surfactants. Triphenylphosphine oxide helped in the formation of smaller nanoparticles due to long chain structure which provided greater steric hindrance. Fourier transform infrared spectroscopy proved that the particles formed are Mo nanoparticles and not metal oxide. The monometallic Pt and Mo, and bimetallic Pt-Mo nanoparticles were supported on functionalized silica colloids. Transmission electron microscopy showed well dispersion of particles on the support. The atomic percentages of both the metals in the supported catalyst were verified by energy dispersive X-ray spectroscopy. The electrochemical application was studied by cyclic voltammetry in the methanol electrooxidation by employing synthesized supported bimetallic nanoparticles. The catalytic efficiency of bimetallic was more than the monometallic nanoparticles, and the order of current densities was Pt50Mo50 > Pt70Mo30 > Pt100Mo0 > Pt0Mo100. The nature of the reaction was observed to be irreversible and diffusion controlled.