Nanoparticles of Ru-Ni synthesized from binary solutions can be used as catalysts in the fuel cell applications. Binary metal nanoparticles of Ru-Ni were synthesized with core and shell nanostructures by flash pyrolysis. Ruthenium chloride and nickel chloride were used as a binary mixture to generate the binary nanoparticles. SEM and TEM images confirmed the formation of eutectic metal deposits of < 15 nm with ruthenium forming the core and nickel forming the shell and Ru-Ni binary metal core and shell nanostructure was obtained. As the size decreased, the melting temperatures of both the components in a binary mixture decreased and a eutectic melting point was much lower than that of the individual components. Though the ruthenium and nickel was present throughout the particle, the concentration of ruthenium was concentrated more at the core of the binary nanoparticle. This is an abstract of a paper presented at the AIChE Annual Meeting and Fall Showcase (Cincinnati, OH 10/30/2005-11/4/2005).