Chapter 3 – Elementary Reactions

The chapter addresses the influence of various factors on elementary reactions and theories which describe such influence. The transition state theory capable of predicting the pre-exponential factors of catalytic reactions is discussed. Approaches for calculation of partition functions of the molecules and activated complexes, taking part in catalytic reactions, are presented. Influence of reaction media properties (dielectric constants, ionic strength), isotope effects and the correlation between activation energy and pre-exponential factor are discussed. Application of steady-state and quasi-equilibrium approximations is described. Relationship between kinetics and thermodynamics is exemplified through Bronsted, Hammett, and Taft equations. Basic principles of microkinetic modeling, which assembles molecular-level information obtained from quantum chemical calculations, atomistic simulations and experiments to quantify the kinetic behavior on a particular catalyst surface, are presented.