Kinetics of Catalyzed Reactions: Mechanisms and Rate Enhancement

Abstract

The kinetics of catalyzed reactions plays a vital role in understanding how chemical processes can be accelerated without altering the overall thermodynamic equilibrium. Catalysts function by providing alternative reaction pathways with lower activation energy, thereby increasing reaction rates while remaining chemically unchanged at the end of the process. This study focuses on the fundamental mechanisms of catalysis and the factors influencing rate enhancement in both homogeneous and heterogeneous systems. The analysis explores various catalytic mechanisms, including adsorption, surface reactions, and desorption steps in heterogeneous catalysis, as well as intermediate complex formation in homogeneous catalysis. Special attention is given to widely studied models such as the Langmuir–Hinshelwood and Eley–Rideal mechanisms, which describe interactions between reactants and catalyst surfaces. The role of active sites, catalyst structure, and surface area in determining reaction rates is also examined. Kinetic parameters such as rate constants, reaction order, and activation energy are evaluated to understand the efficiency of catalytic systems. The Arrhenius equation is utilized to explain the temperature dependence of reaction rates and the reduction of activation energy in the presence of catalysts. Additionally, the influence of mass transfer limitations, diffusion effects, and catalyst deactivation on overall reaction kinetics is discussed.