AVS 54th International Symposium | |
Surface Science | Wednesday Sessions |
Session SS1-WeA |
Session: | Reactions on Metal Surfaces |
Presenter: | D.-J. Liu, Iowa State University |
Authors: | D.-J. Liu, Iowa State University J.W. Evans, Iowa State University |
Correspondent: | Click to Email |
A multisite lattice-gas model1 has been developed to provide a realistic description of the chemisorption of single species (CO, O, etc) on the (100) surface of metals such as Rh, Pd, and Ir. In addition, the model describes more complicated chemisorption and reaction processes for mixed adlayers. Population of various adsorption sites must be incorporated for reliable modeling even for single species on a single surface at higher coverages. For reactions such as CO oxidation in mixed layers, distinct local reaction configurations or pathways can contribute to different peaks observed in the temperature-programmed-reaction (TPR) spectra. Thus, our general multisite lattice-gas model allows populations of different adsorption sites (e.g., bridge, top, and hollow sites) incorporating site-specific binding energy and interactions. Parameters are chosen based on comparison with experimental data and DFT results. In addition, it is necessaary to incorporate very rapid diffusion of the reacting species (with rates many order of magnitude above other rates). We utilize kinetic Monte Carlo simulations to analyze model behavior and to interpret a variety of experimental data (heat of adsorption, TPD, TPR, etc) for the above-mentioned metal surfaces.
1 D.-J. Liu, J. Phys. Chem. C (2007); D.-J. Liu and J. W. Evans, J. Chem. Phys. 124 (2006) 154705.