Microwave plasma synthesis of carbon-supported ultrafine metal particles

Microwave plasma decomposition of metal carbonyls has been used to synthesize a series of carbon-supported monometallic (Fe, Co) and bimetallic (Go-Mo) materials. The average metal particle diameters in all cases were less than 10 nm. By using 10% H-2/Ar instead of pure Ar as a carrier gas, the mean particle diameters could be decreased to less than 2 nm. Although the distribution of particles is slightly broader than those generated by other nanoparticle synthesis methods, the mean diameter of the particles generated using 10% H-2/Ar is as small as any previously reported for Fe-, Co-, Ni-, or Mo-containing compounds. The ultrafine metal particles were dispersed on moderate surface area amorphous carbon support matrixes derived from the concomitant microwave decomposition of the toluene solvent.