Theoretical Studies Of Metal Clusters Supported On Carbon Nanostructures

In this thesis, we studied the properties of clusters supported on the nanosructures, usingthe density functional theory.Firstly, we studied the ground structures and electronic properties of Na_nC₆₀ⁿ（n=1-12）clusters in detail. The calculated vertical detachment energies show good agreement with theexperimental data. The oscillation can be attributed to the combination of the charge depletiondistribution induced by removing electrons and the number of the sodium atoms in directcontact with the fullerene. Based on the structural and electronic properties, the Na atoms canbe categorized into two groups, one is for the metal atoms directly bonded to the fullerenesurface, and the other one is for those without bonding to the fullerene. The Na atoms ingroup one would donate electrons to both the fullerene and the Na atoms in group two. As thetotal number of the sodium atoms increases, the number of Na atoms in group one wouldcontinue increasing till the size n=3p-1to meet a shoulder from n=3p-1to n=3p, whichaccounts for the maximum vertical detachment energy at the size of n=3p as drawn from thedetailed electronic property studies. Based on the study on the properties of the Na atomsadsorbed C₆₀, we have performed a detailed study on the structural and the electronicproperties of M_nC₆₀^±1,0（n=1-12, M=Li, Na, K） clusters. The behaviors of the different alkaliatoms over the C₆₀are different. We give an explanation from the points of the structuralparameters, electronegativity and metallic cohesion.In the second part, we studied the catalytic properties of small magic gold clustersupported on C₄₈B₁₂. We performed an extensive sreaching for the ground structures of theAu_nC₄₈B₁₂clusters and found Au_nC₄₈B₁₂（n=4,6,9） clusters to have high stability which canbe used as the new catalystt nanostructures. As a result of the charge transfer from Au to O₂,the O-O band length is elongated resulting in its high reactity. For the Au4C₄₈B₁₂cluster, thecoadsorption of the CO and O₂molecules can react with an activation energy as small as0.45eV. For the Au₆C₄₈B₁₂and Au₉C₄₈B₁₂clusters, the Eley-Rideal （EK） reaction can happen andthe corresponding energy barriers are0.66and0.67eV respectively.In the last part, we detailed analyzed the FePc sheets functionally modified by thenon-metal atoms and the small molecules. The magnetic moment could be changed from2μBto 0,1,2, and3μBper unit cell for the case of tetra-, penta-, hexa-, and hepta-valent non-matelmodification, respectively. The adsorption of small molecules could also tailor the magneticproperties of FePc sheets. Also, the supporting materials such as the Ag substrate may play animportant role in keeping the magnetism of the FePc complexes.