A supported catalyst is prepared by a process that includes establishing shell-removal conditions for a supported catalyst intermediate that includes capped nanoparticles of a catalyst material dispersed on a carbon support. The capped nanoparticles each include a platinum alloy core capped in an organic shell. The shell-removal conditions include an elevated temperature and an inert gas atmosphere that is substantially free of oxygen. The organic shell is removed from the platinum alloy core under the shell-removal conditions to limit thermal decomposition of the carbon support and thereby limit agglomeration of the catalyst material such that the supported catalyst includes an electrochemical surface area of at least 30 m2/gPt.