Integrated Experimental-Theoretical Approach to Determine Reliable Molecular Reaction Mechanisms on Transition Metal Oxide Surfaces

By combining experimental and theoretical approaches, we investigate the quantitative relationship between molecular desorption temperature and binding energy on d and f metal oxide surfaces. We demonstrate how temperature programmed desorption (TPD) can be used to quantitatively correlate the theoretical surface chemistry of metal oxides (via on-site Hubbard U correction) to gas surface interactions for catalytic reactions. For this purpose, both CO and NO oxidation mechanisms are studied in a step by step reaction process for perovskite and mullite-type oxides, respectively. Additionally, we show solutions for over-binding issues found in CO_x, NO_x, SO_x, and other covalently bonded molecules which must be considered during surface reaction modeling. This work shows the high reliability of using TPD and density functional theory (DFT) in conjunction to create accurate surface chemistry information for a variety of correlated metal oxide materials.