UV Rate Constants

Abstract

Equilibrium considerations can certainly be useful, but catalysis is in the end really all about speeding up a reaction, where the reactants and products are not in equilibrium, so we must be able to address reaction rates to obtain a detailed picture of what goes on at catalytic surfaces under relevant conditions. This chapter postulates an Arrhenius-type expression for rate constants in terms of (an as-of-yet undetermined) prefactor and an activation energy that we could obtain already from the potential energy surface (PES). It specifies exactly what is meant by the term “rate constant” and how it relates to the Gibbs free energy surface. Transition state theory (TST) approaches the problem of calculating a reaction rate for a rarely occurring reactive event by separating the PES into two regions, one being the reactant region (R) and the other being the product region (P).