Iron and ruthenium nanoparticles in carbon prepared by thermolysis of buckymetallocenes.

Thermolysis of fullerene iron and ruthenium complexes (buckymetallocene M(C(60)R(5))Cp (M = Fe; R = Ph (1) and Me (2), M = Ru; R = Ph (3), Me (4)) under a nitrogen atmosphere produced metal nanoparticles dispersed in carbon materials. The thermal degradation processes of the buckymetallocenes were studied by TG-DTA, TEM with a heating sample stage, and VT-XRD. Variation of the thermolysis temperature led to a change in the size of the nanoparticles and the morphology of the carbon materials. Thermolysis of buckyferrocene at 700 degrees C gave highly dispersed iron nanoparticles (average diameter of 7.4 nm). After thermal treatment at 900 degrees C, graphite structures such as carbon nanocapsules and carbon nanotubes formed because of the catalytic activity of the iron nanoparticles. Ruthenium nanoparticles prepared from buckyruthenocene were much smaller than the iron counterparts, and did not catalyze the formation of graphite structures. When buckyruthenocene absorbed on silica gel was heated at 500 degrees C under a hydrogen atmosphere, the resulting ruthenium nanoparticles showed high activity in catalytic hydrogenation.