摘要

The adsorptions of the CO molecule on the neutral mixed clusters of Sn and Ge up to five atoms are investigated theoretically. Electronic structures of the cluster-CO complexes are obtained by global optimization of the energy surface using Monte Carlo simulation coupled with simulated annealing followed by pseudopotential plane wave density functional theory calculations. An aug-cc-pVTZ basis set for C and O and aug-cc-pVTZ-pp for Sn and Ge atoms are employed. The CO adsorption energies and Gibbs free energy are calculated to establish the kinetic and thermodynamic stability of the cluster-CO complexes. The variations of adsorption energy, HOMO-LUMO gap, and NBO charge on CO fragment with the size of the clusters are reported. The CO adsorptions on Sn-Ge mixed clusters are confirmed by studying correlations among different parameters such as the increase in C-O bond length, the red shift in C-O stretching frequency, CO binding energy, changes in Gibbs free energy, and NBO charge on CO.

  • 出版日期2012-11-15