Catalysis spectroscopy

Characterization is an important field in catalysis. Spectroscopy, microscopy, diffraction and methods based on adsorption and desorption or bulk reactions (reduction, oxidation) all offer tools to investigate the nature of an active catalyst. With such knowledge we hope to understand catalysts better, so that we can improve them or even design new catalysts. 

Biological inorganic and coordination compounds Organo-metallic and molecular synthesis and catalysis Spectroscopy... 

Metal nanopartieles have been shown to be important for catalysis, spectroscopy, optoelectronic devices, and magnetic data storage. Successful exploitation of metallic nanopartieles lies in the successful conjugation of their active surface structure. Thus, size and shape play a role in terms of variable surface energy. This becomes paradoxical when surface activity and stabilization are examined both surface activity and particle stabilization need to be controlled. Thus, proper support becomes inevitably a unique choice, which simultaneously can promote surface activity and provide stabilization to the metallic nanopartieles for innumerable applications. Proper support stabilizes metal nanopartieles of different sizes and shapes but not at the cost of surface activity. At this time, only a few achievements are promising. In an analogous fashion, metal oxides, generally transition metal oxides, are robust and are the future material of choice for supports. 

Stenoel J M 1990 Raman Spectroscopy for Catalysis (New York Van Nostrand Reinhold)... 

Delgass W N, Haller G L, Kellerman R and Lunsford J H 1979 Spectroscopy in Heterogeneous Catalysis (New York Academic)... 

Woodruff D P and Delohar T A 1986 Modern Techniques of Surface Science (Cambridge Cambridge University Press) Niemantsverdriet J W 1993 Spectroscopy in Catalysis, an Introduction (Weinheim VCH)... 

Karge FI G, Flunger M and Beyer FI K 1999 Characterization of zeolites—infrared and nuclear magnetic resonance spectroscopy and x-ray diffraction Catalysis and Zeolites, Fundamentals and Applications ed J Weitkamp and L... 

Laser stimulation of a silver surface results in a reflected signal over a million times stronger than that of other metals. Called laser-enhanced Raman spectroscopy, this procedure is useful in catalysis. The large neutron cross section of silver (see Fig. 2), makes this element useful as a thermal neutron flux monitor for reactor surveillance programs (see Nuclearreactors). 

Chemical appHcations of Mn ssbauer spectroscopy are broad (291—293) determination of electron configurations and assignment of oxidation states in stmctural chemistry polymer properties studies of surface chemistry, corrosion, and catalysis and metal-atom bonding in biochemical systems. There are also important appHcations to materials science and metallurgy (294,295) (see Surface and interface analysis). 

W. A. Nugent and J. M. Mayer, Metal-Eigand Multiple Bonds The Chemistry of Transition Metal Complexes Containing Oxo, Nitrido, Imido, Jilkylidene, orJilkylidyne Eigands,Jolm. Wiley Sons, Inc., New York, 1988. Contains electronic and molecular stmcture, nmr, and ir spectroscopy, reactions, and catalysis. 

The lecture deals with the advantages of IR spectroscopy at low or variable temperatures in the studies of molecule-surface interactions, lateral interactions between the adsorbed molecules and catalysis. 

In this chapter shock modification of powders (their specific area, x-ray diffraction lines, and point defects) measurements via analytical electron microscopy, magnetization and Mossbauer spectroscopy shock activation of catalysis, solution, solid-state chemical reactions, sintering, and structural transformations enhanced solid-state reactivity. 

The technique of photoemission electron spectroscopy (PEEM) is a particularly attractive and important one for spatially resolved work function measurements, as both the Kelvin probe technique and UPS are integral methods with very poor ( mm) spatial resolution. The PEEM technique, pioneered in the area of catalysis by Ertl,72-74 Block75 76 and Imbihl,28 has been used successfully to study catalytic oscillatory phenomena on noble metal surfaces.74,75... 

G. Meitzner, and E. Iglesia, New insights into methanol synthesis catalysts from X-ray absorption spectroscopy, Catalysis Today 53, 433-441 (1999). 

In order to get the pore system of zeolites available for adsorption and catalysis the template molecules have to be removed. This is generally done by calcination in air at temperatures up to 500 °C. A careful study (ref. 12) of the calcination of as-synthesized TPA-containing MFI-type single crystals by infrared spectroscopy and visible light microscopy showed that quat decomposition sets in around 350 °C. Sometimes special techniques are required, e.g. heating in an ammonia atmosphere (ref. 13) in the case of B-MFI (boron instead of aluminum present) to prevent loss of crystallinity of the zeolite during template quat removal. 

Figure 4.3 shows some statistics on the use of characterization techniques in catalysis. In this chapter we briefly introduce the most important of these methods and illustrate their use. Further examples can be found in subsequent chapters and in J.W. Niemantsverdriet, Spectroscopy in Catalysis, An Introduction (2000), Wiley-VCFI, Weinheim. 

Baltimore, 1996 [Reproduced from J.W. Niemantsverdriet, Spectroscopy in Catalysis, An Introduction (2000), Wiley-VCH, Weinheim]. 

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