A process is provided that involves contacting a metal substrate with a bath. The bath includes one or more metallic precursors and one or more organic solvents. The process also includes conducting a replacement reaction between the metal substrate and the one or more metallic precursors. The replacement reaction is conducted under controlled reaction conditions sufficient to produce one or more substrate cored-metal layer shelled metal alloys. Substrate cored-metal layer shelled metal alloys prepared by the process of this disclosure are also provided. The substrate cored-metal layer shelled metal alloys of this disclosure can have many important applications, such as functioning as heterogeneous catalysts in fuel reforming processes and as electrode materials in thin film Li batteries for energy storage.