Density Functional Theory Study of Geometrical and Electron Structures of Al18Ti Aluminum Clusters and Their Catalytic Activity toward the CO Oxidation

Abstract

The B3LYP functional in conjunction with 6-311+G(d) basis set was employed to optimize geometrical structures, followed by frequency calculations of the Al₁₉⁺ and Al₁₈Ti clusters, converging to the double icosahedron structure, and the Ti places at the top apex of the double icosahedron in the case of Al₁₈Ti cluster. The changes in the electron structure of the clusters have been determined; accordingly, there is energy level splitting of the 1P, 1D, 1F, 2P, and 2D shell orbitals and the appearance of 3d orbitals of the Ti in the electron configurations. The catalytic ability of the Al₁₈Ti cluster for the CO and O₂ reaction has been investigated initially; thus, the Ti atom plays a central role in binding to CO and O₂, weakening both the O=O and C≡O bonds and facilitating the formation of CO₂.