The present invention encompasses methods and apparatus for creating metal nanoparticles embedded in a carbonaceous char, the conversion of an carbonaceous char with embedded metallic nanoparticles to graphite-encased nano-sized metal particles surrounded by char, the separation of the graphite encased metal particles from the char matrix, and the related preparation and isolation of carbon nanosphere materials with or without the enclosed metal nanoparticles, and the uses of such carbon nanospheres and graphite enclosed metal nanoparticles as supports and enhancers for fuel cell electrocatalysts and other applications.