All real solid surfaces are heterogeneous to a greater or lesser extent and this book provides a broad yet detailed survey of the present state of gas adsorption. Coverage is comprehensive and extends from basic principles to computer simulation of adsorption. Underlying concepts are clarified and the strengths and weaknesses of the various methods described are discussed. - Adsorption isotherm equations for various types of heterogeneous solid surfaces - Methods of determining the nature of surface heterogeneity and porosity from experimental data - Studies of phase behavior of gases absorbed on heterogeneous solid surfaces - Computer simulation of adsorption on heterogeneous solid surfaces

The fact that the surfaces of real solids are geometrically distorted and chemically non-uniform has long been realized by the scientists investigating various phenomena occurring on solid surfaces. Even in the case when diffraction experiments show a well-organized bulk solid structure, the surface atoms or molecules will usually exhibit a much smaller degree of surface organization. In addition to the results obtained from electron diffraction, this can be seen in the impressive images obtained from STM and AFM microscopies. This geometric and chemical disorder is the source of the energetic heterogeneity for molecules adsorbing on real solid surfaces. Hundreds of papers have been published showing that this heterogeneity is a major factor in determining the behaviour of real adsorption systems.Studies of adsorption on energetically heterogeneous surfaces have proceeded along three somewhat separate paths, with only minor coupling of ideas. One was the study of adsorption equilibria on heterogeneous solid surfaces. The second path was the study of time evolution of adsorption processes such as surface diffusion or adsorption-desorption kinetics on heterogeneous surfaces, and the third was the study of adsorption in porous solids, or more generally, adsorption in systems with limited dimensions. The present monograph is a first attempt to provide a synthesis of the ways that surface geometric and energetic heterogeneities affect both the equilibria and the time evolution of adsorption on real solids. The book contains 17 chapters written by a team of internationally recognized specialists, some of whom have already published books on adsorption.

This book presents a unified description of physical adsorption on heterogeneous solids from both the gas and liquid phases. All solid adsorbents of great practical importance, such as activated carbons, silica gels, aluminium oxides, zeolites, etc., possess surface and structural heterogeneities, which play a dominant role in the adsorption process especially at low pressures. The assumption of adsorbent heterogeneity in studies of physical adsorption introduces considerable difficulties in the theoretical description of this phenomenon. To overcome this problem, the authors have presented a relatively simple theory of physical adsorption on heterogeneous solids, which provides a quantitative description of this phenomenon and simultaneously permits elaboration of methods for characterizing adsorbent heterogeneity. The chapter on single-gas adsorption on heterogeneous surfaces is the most extensive one in the book because there is a great deal of scientific literature concerning this problem. Moreoever, the theory of single-gas adsorption provides foundations for deriving equations that apply to adsorption from multicomponent gas and liquid mixtures.

The declared objective of this book is to provide an introductory review of the various theoretical and practical aspects of adsorption by powders and porous solids with particular reference to materials of technological importance. The primary aim is to meet the needs of students and non-specialists who are new to surface science or who wish to use the advanced techniques now available for the determination of surface area, pore size and surface characterization. In addition, a critical account is given of recent work on the adsorptive properties of activated carbons, oxides, clays and zeolites. - Provides a comprehensive treatment of adsorption at both the gas/solid interface and the liquid/solid interface - Includes chapters dealing with experimental methodology and the interpretation of adsorption data obtained with porous oxides, carbons and zeolites - Techniques capture the importance of heterogeneous catalysis, chemical engineering and the production of pigments, cements, agrochemicals, and pharmaceuticals