Heterogeneous catalysis, role

The reader must have already identified some of the basic concepts which play a key role in understanding the electrochemical activation of heterogeneous catalysis catalysis, electrocatalysis, promotion, electrochemical promotion, spillover, backspillover. It is therefore quite important to define these terms unambiguously so that their meaning is clearly determined throughout this book. 

There is a very rich literature and a comprehensive book6 on the role of promoters in heterogeneous catalysis. The vast majority of studies refers to the adsorption of promoters and to the effect of promoters on the chemisorptive state of coadsorbed species on well characterized single crystal surfaces. A... 

The effect of spillover plays an important role in heterogeneous catalysis and was extensively studied during recent years. It was first noticed in the 1950s by Kuriacose.62 Work in this area has been reviewed by Teichner63 and by Conner et al.64... 

Control of emissions of CO, VOC, and NOj, is high on the agenda. Heterogeneous catalysis plays a key role and in most cases structured reactors, in particular monoliths, outperform packed beds because of (i) low pressure drop, (ii) flexibility in design for fast reactions, that is, thin catalytic layers with large geometric surface area are optimal, and (iii) attrition resistance [17]. For power plants the large flow... 

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. 

X-ray photoelectron spectra, V3f Alumina-supported metals, multitechnique characterization, 37V-83 Aluminosilicates, Intercalates of, role In heterogeneous catalysis, V72-83 Alumlmin... 

As an alternative approach towards the above requirement, Somorjai introduced the method of electron lithography [119] which represents an advanced HIGHTECH sample preparation technique. The method ensures uniform particle size and spacing e.g. Pt particles of 25 nm size could be placed with 50 nm separation. This array showed a uniform activity similar to those measured on single crystal in ethylene hydrogenation. The only difficulty with the method is that the particle size is so far not small enough. Comprehensive reviews have been lined up for the effect of dispersion and its role in heterogeneous catalysis [23,124,125]. 

In heterogeneous catalysis catalyst characterization plays an important role. It is fair to state that improved characterization techniques have been the major drive towards the development of heterogeneous catalysis as a mature technology. 

The Role of the Adsorbed State in Heterogeneous Catalysis, Discuss. Faraday Soc., 1966, No. 41. 

A discussion along this line has been made in regard to the orientation of the hydrogen molecule in the dissociative adsorption on metals 82>. Thus, the interpretation of the function of heterogeneous catalysis on a molecular basis is no longer beyond our reach. The important role of LU MO in the process of polarographic reductions has also been discussed... 

Of course, other reaction types have been also investigated more recently, such as the Beckmann rearrangement [247,277,278] or ethylbenzene disproportionation [279, 280], just to name a couple. In situ NMR methods are expected to play a vital role in the future science of heterogeneous catalysis. 

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