Chemical Reactions and Complexity

It is a well-established fact that most chemical reactions are of a complex nature. The existence of the intermediates and their corresponding reactions has been confirmed by independent spectroscopic measurements. The detailed reaction mechanism can be represented by the set of elementary steps. The reaction mechanism, or equivalently, mechanism, is the fundamental concept of chemical kinetics, which reflects the complexity of the chemical reaction. In a broad sense, the term mechanism is the comprehensive interpretation of all experimental data accumulated on a complex chemical reaction process. In the case of heterogeneous gas-solid catalytic reactions, reactants in elementary steps can be gas-phase components or surface intermediates. The rate of an elementary reaction can be defined as the number of elementary acts of chemical transformation per unit volume of the reaction mixture per unit time. A chemical reaction is complex and consists of elementary reactions for which the kinetic law is assumed to be known.