The Electronic Factor in Heterogeneous Catalysis

This chapter discusses the origin of the surface specificity of adsorption energies and activation energies for surface reactions. It begins with the discussion of how the electronic structure of a surface determines the reactivity, and identifies the most important electronic structure parameters. The chapter provides a qualitative model of electronic factors in heterogeneous catalysis. The simplest model would be to use data of pure metal surfaces alone and not taking into account strain and ligand effects induced by the host material. The chapter concentrates only on the reactivity of transition metal surfaces and shows that trends in adsorption energies and activation energies from one system to the next can be understood in terms of variations in the local d DOS, in particular the d-band center. The chapter ends by indicating that similar concepts can be developed to understand trends in reactivity for transition metal compounds.