Hydrogenation of C60 on alumina-supported nickel and thermal properties of C60H36
Abstract
Hydrogenation of C60 was carried out in toluene using Ni/Al2O3 catalyst. C60H36 was obtained in the temperature range 150–250°C and the hydrogen pressure range 25–75 kgf cm-2 (1 kgf=9.80665 N). Degradation of the fullerene giving lighter hydrocarbons was not observed under the experimental conditions. C60 conversion was estimated from the decrease of absorbance of solution at 600 nm and compared with toluene conversion to methylcyclohexane. C60 hydrogenation was faster than toluene hydrogenation. Thermogravimetry and differential thermal analysis of C60H36 were performed in air and compared with those of C60, active carbon and diamond. C60H36 was partially oxidized at 277°C giving C60H36Ox (x=ca. 4.8) followed by combustion at 472°C. The temperature was much lower than that of C60, of which the partial oxidation and the combustion were observed at 432 and 615°C, respectively. The number of oxygen atoms added was larger for C60H36 than for C60. These results strongly suggest that C60H36 is more reactive for oxygen than C60.