The decomposition of C60 on nickel clusters

Abstract

The adsorption of C60 on nickel clusters Nin in the n=8–31 size range is studied at elevated temperatures. Above 800 °C, decomposition of C60 is seen on clusters containing oxide impurities by the loss of CO and/or CO2 molecules. The extent of decomposition depends on cluster size and C60 coverage, which affect the charging of the metal core by electron transfer from the metal to the C60. Both decreased cluster size and increased C60 coverage reduce the electron transfer per C60 molecule, weakening the C60–Nin bond and decreasing the rate of decomposition. In spite of this effect, C60 appears to decompose more readily on small nickel clusters than on bulk nickel surfaces. While decomposition is only observed for clusters having adsorbed O atoms, the oxygen may actually inhibit decomposition by withdrawing electronic charge from the metal, likewise weakening the C60–Nin bond.