DYNAMICS OF CO CHEMISORPTION ON A METAL CLUSTER

The understanding of the dynamics of collisions between molecules and small metal clusters is an important component of a general understanding of practical heterogeneous catalytic processes. We report here quasiclassical trajectory studies of CO colliding with a five-atom metal cluster, with our primary focus being on the modeling of collisions with a copper cluster. Since the forces in these systems are still largely unknown, we have considered a number of simple potential-energy parametrizations so as to determine the range of behavior which might be expected. In general, CO is found to add readily to the metal cluster, forming a complex which is stable on the time scale of the trajectories. The effects of variations in the cluster geometry and extensions to systems having higher molecule-cluster binding energies are also considered here, as is the question of whether or not there is a significant distortion of the metal cluster geometry upon addition of CO. This last topic is conveniently approached via a combination of trajectory and Monte Carlo simulated annealing techniques. © 1990 American Institute of Physics.