Enumeration and discrimination of mechanisms in heterogeneous catalysis based on response reactions and unity bond index-quadratic exponential potential (UBI-QEP) method

The problem of a complete enumeration of a unique set of overall reactions and the corresponding mechanisms from a given set of elementary reactions is discussed in terms of the recently introduced concept of response reactions. A simple algorithm for the systematic generation of direct overall reactions and direct mechanisms from the given set of elementary reactions is presented. Further, based on energetic characteristics of the surface elementary reactions, i.e. the enthalpy changes and activation energy barriers, calculated by using the unity bond index-quadratic exponential potential (UBI-QEP) method, a qualitative procedure for the selection of energetically the most favorable direct mechanisms is proposed. These theoretical considerations are illustrated by a detailed analysis of the mechanism of methanol synthesis on copper catalyst.