Nanostructured catalysts have application in the area of fuel cells for advanced propulsion systems, non-polluting electric vehicles and portable devices. Currently, low activity, poor durability and high cost of the platinum-based anode and cathode catalysts in PEMFCs and DMFCs constitute some of the major barriers to commercialization of fuel cells. This presentation reports novel findings of an investigation of core@shell nanoparticles (Au@Pt, Pt@Au, Fe3O4@Au@Pt) and their electrocatalytic properties for methanol oxidation reaction and oxygen reduction reaction. The electrocatalytic activities depend on the size and composition of the core and the shell. Implications of the results to the design of the desired nanoscale catalysts will also be discussed.