Laser-Stimulated Surface Processes and Heterogeneous Catalysis

摘要

A theoretical study of laser-stimulated surface processes (LSSP), motivated by potentialities in the areas of chemical industrial, material science and academic research, is presented. The possibility of the new phenomena of laser-controlled surface processes (migration, recombination, desorption and heterogeneous rate processes) is demonstrated within the framework of model systems which create a theoretical foundation for an understanding of the quantitative and semi-quantitative aspects of LSSP, and provide possible mechanisms and suggest relevant measurements of LSSP with applications to laser-catalyzed rate processes. For a heterogeneous system of LSSP, the major features and the dynamical behavior are studied by both classical and quantum models, where each model provides one or more mechanism of the processes. They include: microscopic model Hamiltonians (in the Heisenberg-Markovian picture) of multiphoton-multiphonon processes; quantum dynamical model (in the Schrodinger picture) of the selective vs nonselective nature of LSSP; Pauli master equations in photon-energy space for the energy distributions and associated desorption probabilities of the adspecies; phenomenological classical models for the average power absorption of the system, where the many-body effects of the surface atoms are replaced by the damping factor and the frequency-shift; the generalized Langevin theory for the dynamical behavior of LSSP; coupled Newton's equations of a model CO/Ni adspecies/surface system for the numerical simulation of the atom amplitudes and the energies stored in the bonds; and semiclassical model for the laser-selective nature via the multiphonon coupling strength and the internal resonant condition.