Isotopic Assessment of Heterogeneous Catalysis deals with the use of isotopic tracing to study the reaction mechanisms involved in heterogeneous catalysis. It presents special methods for using isotopic and radioactive atomic species for obtaining meaningful kinetic data that can be quantitatively used in mechanistic modeling. It also considers a number of industrial reactions under steady-state reaction conditions in which superposed tracer transfer is also at steady state. This book is comprised of eight chapters and begins with an introduction to heterogeneous catalysis and an approach to reaction modeling, as well as the experimental reactors for obtaining the type of measurements and data needed in transient modeling. The application of isotopes in studies of heterogeneous catalysis is also discussed. Subsequent chapters focus on the choice of intermediates and reaction steps in tracer experiments; the number of overall stoichiometric chemical reactions that can occur in order to generate product molecules from reactants; superposition modeling of mechanisms; and steady-state tracing. Transient tracing and the development of rate equations are also described. This monograph is intended primarily for students and teachers of such subjects as physical chemistry, as well as research scientists and technologists.

This study has developed a complete procedure for the measurement of oxygen isotopes in arsenic oxyanions in natural waters by using different adsorbents. The experimental results of kinetic exchange of oxygen between AsO43- and water show that the entire exchange procedure happens in a very short time at different pH conditions and temperatures.

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.