Heterogeneous catalysis, theory

THE VALENCY EFFECT HETEROGENEOUS CATALYSIS THEORY CALCULATIONS... 

The Application of the Theory of Semiconductors to Problems of Heterogeneous Catalysis... 

On the Theory of Heterogeneous Catalysis Jcro Horiuti and Takashi Nakamura Linear Correlations of Substrate Reactivity in Heterogeneous Catalytic Reactions M- Kraus... 

Modem State of the Multiplet Theory of Heterogeneous Catalysis A. A. Balandin... 

Models and theories have been developed by scientists that allow a good description of the double layers at each side of the surface either at equilibrium, under steady-state conditions, or under transition conditions. Only the surface has remained out of reach of the science developed, which cannot provide a quantitative model that describes the surface and surface variations during electrochemical reactions. For this reason electrochemistry, in the form of heterogeneous catalysis or heterogeneous catalysis has remained an empirical part of physical chemistry. However, advances in experimental methods during the past decade, which allow the observation... 

Theoretically, the problem has been attacked by various approaches and on different levels. Simple derivations are connected with the theory of extrathermodynamic relationships and consider a single and simple mechanism of interaction to be a sufficient condition (2, 120). Alternative simple derivations depend on a plurality of mechanisms (4, 121, 122) or a complex mechanism of so called cooperative processes (113), or a particular form of temperature dependence (123). Fundamental studies in the framework of statistical mechanics have been done by Riietschi (96), Ritchie and Sager (124), and Thorn (125). Theories of more limited range of application have been advanced for heterogeneous catalysis (4, 5, 46-48, 122) and for solution enthalpies and entropies (126). However, most theories are concerned with reactions in the condensed phase (6, 127) and assume the controlling factors to be solvent effects (13, 21, 56, 109, 116, 128-130), hydrogen bonding (131), steric (13, 116, 132) and electrostatic (37, 133) effects, and the tunnel effect (4,... 

Among the theories of limited applicability, those of heterogeneous catalysis processes have been most developed (4, 5, 48). They are based on the assumption of many active sites with different activity, the distribution of which may be either random (23) or thermodynamic (27, 28, 48). Multiple adsorption (46, 47) and tunnel effects (4, 46) also are considered. It seems, however, that there is in principle no specific feature of isokinetic behavior in heterogeneous catalysis. It is true only that the phenomenon has been discovered in this category and that it can be followed easily because of large possible changes of temperature. 

Gas-surface interactions and reactions on surfaces play a crucial role in many technologically important areas such as corrosion, adhesion, synthesis of new materials, electrochemistry and heterogeneous catalysis. This chapter aims to describe the interaction of gases with metal surfaces in terms of chemical bonding. Molecular orbital and band structure theory are the basic tools for this. We limit ourselves to metals. 

Balandin A. 1969. Modem state of the multiplet theory of heterogeneous catalysis. Adv Catal 19 1. 

This series covers recent advances in electrocatalysis and electrochemistry and depicts prospects for their contribution into the present and future of the industrial world. It illustrates the transition of electrochemical sciences from a solid chapter of physical electrochemistry (covering mainly electron transfer reactions, concepts of electrode potentials and stmcture of the electrical double layer) to the field in which electrochemical reactivity is shown as a unique chapter of heterogeneous catalysis, is supported by high-level theory, connects to other areas of science, and includes focus on electrode surface structure, reaction environment, and interfacial spectroscopy. 

Elementary reactions on solid surfaces are central to heterogeneous catalysis (Chapter 8) and gas-solid reactions (Chapter 9). This class of elementary reactions is the most complex and least understood of all those considered here. The simple quantitative theories of reaction rates on surfaces, which begin with the work of Langmuir in the 1920s, use the concept of sites, which are atomic groupings on the surface involved in bonding to other atoms or molecules. These theories treat the sites as if they are stationary gas-phase species which participate in reactive collisions in a similar manner to gas-phase reactants. 

Nalewajski, R. F.1997. Consistent two-reactant approach to chemisorption complexes in charge sensitivity analysis. In Developments in the Theory of Chemical Reactivity and Heterogeneous Catalysis. (Eds.) W. M. Mortier, and R. A. Schoonheydt, pp. 135-196. Trivandrum Research Signpost. 

The Intermediate Compound Theory in Homogeneous and Heterogeneous Catalysis. 51... 

The heterogeneous catalysis e.g. gaseous reaction on a solid surface, is explained by this theory as follows ... 

Every heterogeneous catalytic process begins with the act of adsorption. Therefore, the theory of heterogeneous catalysis should proceed from the... 

---