• carbon;
  • fullerenes;
  • iron;
  • nanoparticles;
  • ruthenium


Thumbnail image of graphical abstract

Turn up the heat! Iron and ruthenium nanoparticles in carbon have been prepared by thermolysis of iron and ruthenium fullerene complexes at 500–900 °C in nitrogen. Differences in their size, formation processes, and catalytic activities have been characterized using TG-DTA, VT-TEM, and VT-XRD analyses.

Thermolysis of fullerene iron and ruthenium complexes (buckymetallocene M(C60R5)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 °C gave highly dispersed iron nanoparticles (average diameter of 7.4 nm). After thermal treatment at 900 °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 °C under a hydrogen atmosphere, the resulting ruthenium nanoparticles showed high activity in catalytic hydrogenation.