Catalysis studies

McIntyre B J, Salmeron M and Somorjai G A 1993 A variable pressure/temperature scanning tunnelling microscope for surface science and catalysis studies Rev. Sc/. Instrum. 64 687... 

CaUilyst Precursor C luster Ref. (Cluster Syntheses) Catalyzed Reaction Ref. (Catalysis Studies)... 

In the various sections of this article, it has been attempted to show that heat-flow calorimetry does not present some of the theoretical or practical limitations which restrain the use of other calorimetric techniques in adsorption or heterogeneous catalysis studies. Provided that some relatively simple calibration tests and preliminary experiments, which have been described, are carefully made, the heat evolved during fast or slow adsorptions or surface interactions may be measured with precision in heat-flow calorimeters which are, moreover, particularly suitable for investigating surface phenomena on solids with a poor heat conductivity, as most industrial catalysts indeed are. The excellent stability of the zero reading, the high sensitivity level, and the remarkable fidelity which characterize many heat-flow microcalorimeters, and especially the Calvet microcalorimeters, permit, in most cases, the correct determination of the Q-0 curve—the energy spectrum of the adsorbent surface with respect to... 

H.H. Brongersma and G.C. van Leerdam, in Fundamental Aspects of Heterogeneous Catalysis Studied by Particle Beams, H.H. Brongersma and R.A. van Santen (Eds.), NATO ASI Scries B,... 

Because of their electronic properties, particularly their visible-ultraviolet band gap, tungsten oxides have been the focus of a number of catalysis studies. Kohler and Gopel examined the electrocatalytic properties of W02.72 using spectroscopic surface... 

The interest in highly branched polynuclear metal complexes, and more generally in dendritic species, is related not so much to their size, but rather to the presence of different components. An ordered array of different components can in fact generate valuable properties, such as the presence of cavities having different size, surfaces with specific functions, gradients for photoinduced directional energy and electron transfer, and sites for multielectron transfer catalysis. Studies along these directions are underway in our laboratories. 

VII. The Relation of Mononuclear Surface Oxygen Species to Electron Spectroscopic and Catalysis Studies... 

Studies of I /Ru stoichiometry previously discussed and shown in Fig. 20 suggest that these two complexes, or at least a catalyst composition of the same stoichiometry, are present during catalysis. Studies of active solutions during catalysis by high-pressure infrared spectroscopy have also confirmed the presence of these complexes (191). Under 544 atm of H2/CO at 230°C in sulfolane solvent, the infrared absorptions for the carbonyl ligands of both complexes are observed clearly. No other carbonyl absorptions are evident. Samples have also been withdrawn from catalytic reactions and cooled immediately to low temperature before analysis by infrared spectroscopy these solutions also are found to contain only [HRu3(CO)j J and [Ru(CO)3I3]. ... 

Agitated tank reactors Batch agitated reactor This is a batch stirred tank reactor. For liquid-solid systems, the liquid is agitated by a mechanical apparatus (impeller) and the reactor is of tank shape. For gas-solid systems, the gas is agitated and rapidly circulated through a fixed-bed of solids. This reactor is basically an experimental one used for adsorption, ion exchange, and catalysis studies. 

So far, the bonding and surface structure aspects of electrocatalysis have been presented in a somewhat abstract sort of way. In order to make electrocatalysis a little more real, it is helpful to go through an example—that of the catalysis of the evolution of oxygen from alkaline solutions onto substances called perovskites. Such materials are given by the general formula RT03, where R is a rare earth element such as lanthanum, and T is a transition metal such as nickel. In the electron catalysis studied, the lattice of the perovskite crystal was replicated with various transition metals, i.e., Ni, Co, Fe, Mn, and Cr, the R remaining always La. 

T. S. R. Prasad Rao, in Recent Advances in Basic and Applied Aspects of Industrial Catalysis, Studies in Surface Science and Catalysis, Vol. 113, T. S. R. Prasad Rao and G. Murali Dhar, eds., Elsevier, Amsterdam, 1998, p. 3. 

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