Pure and Applied Chemistry

Abstract: The last decade has seen rapid expansion and development in the field of density functional theory (DFT) simulation on the complex chemical processes that occur at surfaces and interfaces. The understanding of the phenomena in surface science and heterogeneous catalysis has benefited tremendously from these quantum mechanic calculations. This article reviews current progress in the theory of reactions on surfaces, in particular, those relevant to the barrier and the active site of surface reactions. Two representative reactions, namely, NO dissociation and CO oxidation, are selected to illustrate how these theoretical concepts are applied to understand catalytic reactions. Here, the pathways and energetics of these reactions under various catalytic conditions are described in detail, and the understanding of the reactions is generalized. It is concluded that DFT-based methods can be well applied to catalysis to understand the electronic structure of chemical processes and to elucidate mechanisms of complex surface reactions.