US Patent 10454114 Method of producing stable, active and mass-producible Pt

A method of forming metallic particles, comprising: providing precursor particles comprising a transition metal alloy; supplying carbon monoxide (CO) under reaction conditions which differentially remove a first alloy metal from the precursor particles at a faster rate than a second alloy metal; and, maintaining the reaction conditions until the precursor particles are converted to the particles. The precursor particles may comprise PtNi4, and the particles may be Pt3Ni, formed as hollow nanoframes on a carbon support.