This grant is in the general field of analytical and surface chemistry and in the subfield of reaction dynamics at gas metal interfaces. Professor W. Henry Weinberg of the University of California at Santa Barbara will continue his studies of the reactions of gases at well defined metal surfaces. The focus of the current work will be the understanding of the details of the promotion and poisoning of the dissociative adsorption reactions of nitrogen, oxygen and carbon dioxide at ruthenium surfaces. Further studies with more complex polyatomic molecules will also be done. Simulations of the reaction dynamics will be accomplished to determine the effects of specific reaction channels in the adsorption process. The results of this work will lead to an understanding of the factors governing catalytic reactions and the thermodynamics of reactions at the interface. Several related issues in reaction dynamics will be explored. Molecular beam chemistry with the Ru(001) interface will be explored with vibrational spectroscopy of the adsorbates, following the products of complex surface reactions. Local surface coverage effects will be explored by studying oxygen chemisorption on the Ru surface as a function of order in the monolayer. Surface temperature modulation will be used to follow the reaction coordinates and quantify the reaction rate coefficients of a branching unimolecular dissociation reaction. Monte Carlo simulations of second order surface reactions will explore compensation effects in kinetic parameters.
