The present invention provides a method of producing ultrathin palladium-transitional metal composite nanowires. The method comprises mixing a palladium salt, a transitional melt salt, a surfactant and a phase transfer agent to form a mixture. The transitional metal is selected from the first row transitional metals. A reducing agent is added to the mixture; and the nanowires are isolated. The relative amount of the palladium and the transitional metal in the mixture correlate to the atomic ratio of the palladium and transitional metal in the composite nanowires. The amount of palladium is at least 60%. The diameters of the composite nanowires are from about 1 nm to about 10 nm.