Adsorption, chemisorption, and catalysis

Abstract

AbstractA short history of the relationships among adsorption, chemisorption, and catalysis with solid catalysts is reviewed. A special focus is on the development of quality and descriptions accuracy using computers, both for the modeling of elementary physical phenomena and adsorption, as well as for the solution of more complex problems like quantum chemical approach to chemisorption, kinetics over solid catalysts, and reactor systems. Modern approaches to the characterization of solid catalysts from the adsorption-desorption data based mainly on n-layer adsorption and non-linear three parameter BET isotherm regarding the volume of micropores as one of the parameters are demonstrated. Instrumentation techniques like infrared spectroscopy or NMR techniques for the analysis of the strength of component chemisorption are mentioned. As for the kinetics, a vague capability of the Langmuir-Hinshelwood-Hougen-Watson models to describe a reaction system in more complicated cases, e.g. bimolecular surface reactions, is discussed. In this context, the simplest model with a minimum number of parameters is advised. To estimate the most realistic values, intrinsic reaction kinetic and mass transport phenomena are taken into account. Usefulness of quantum mechanistic models for better understanding of the catalytic phenomena and more efficient design of catalysts are outlined.