Applications in Environmental Catalysis

the preparation by catalytic reduction of multimetallic catalysts for application in water denitration was extended to other bimetallic nanoparticles such as Pt-Ag [35], Pd-Cu [33, 35-37], Pd-Sn [38], Cu-Pt (8), Cu-Pd [8] or to trimetallic nanoparticles such as Pd-Sn-Au [46], deposited on various supports. 

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Frache, A., Gianotti, E. and Marchese, L. (2003) Spectroscopic characterisation of micro-porous aluminophosphate materials with potential application in environmental catalysis, Catal. Today, 77, 371. 

In this section preparation and characterization of catalytic materials are briefly reviewed with respect to their applications in environmental catalysis. A number of techniques for the preparation of the supports and catalysts are emphasized. Techniques such as impregnation, homogeneous deposition precipitation, grafting, hydrolysis, sol-gel, and laser-activated pyrolysis are used for the preparation of catalysts for fundamental studies. 

Labhsetwar, N.K., Watanabe, A., and Mitsuhashi, T. (2003) New improved syntheses of LaRu03 perovskites and their applications in environmental catalysis. Appl Catal B, 40 (1), 21-30. 

In fhe cafalysf preparation, not only the choice of the active phase precursor is cra-cial, the method of catalyst preparation is decisive, too, for obtaining good dispersion of the active phase. Active phase can be deposited on supports by impregnation, ion-exchange, adsorption, etc. Once selected the nature of support and active phase, the observed differences in dispersion should only be due to the method of preparation. Dispersed iron oxide catalysts (FeOx) have received much attention because their potentiality for many applications in environmental catalysis (N2O decomposition and reduction) and in fine chemical industry (Friedel-Crafts, isomerisations, etc.). For most applications, high dispersion of the metal centres is desirable to enhance the activity-selectivity pattern of the catalysts. 

Ionic liquids, which can be defined as salts that do not crystallize at room temperature [46], have been intensively investigated as environmentally friendly solvents because they have no vapor pressure and, in principle, can be reused more efficiently than conventional solvents. Ionic liquids have found wide application in organometallic catalysis as they facilitate the separation between the charged catalysts and the products. 

In fact, most of us benefit from the use of catalysis. Automotive catalytic converters have represented the most massive application of environmental catalysis and one of the most challenging and successful cases in catalysis, generally. Automobile catalysts deseive a few more comments. The engine exhaust emission is a complex mixture, whose composition and flow rate change continuously depending on a variety of factors such as driving conditions, acceleration, and speed. Despite the variability of the conditions, three-way catalysts have achieved the reduction of exhaust carbon monoxide, hydrocarbons, and... 

It is fair to state that by and large the most important application of structured reactors is in environmental catalysis. The major applications are in automotive emission reduction. For diesel exhaust gases a complication is that it is overall oxidizing and contains soot. The three-way catalyst does not work under the conditions of the diesel exhaust gas. The cleaning of exhaust gas from stationary sources is also done in structured catalytic reactors. Important areas are reduction of NOv from power plants and the oxidation of volatile organic compounds (VOCs). Structured reactors also suggest themselves in synthesis gas production, for instance, in catalytic partial oxidation (CPO) of methane. 

Monolithic reactors, similar to many other structured reactors, offer high precision combined with a high efficiency. They are a valuable tool for process intensification. Most practical applications of these reactors are found in environmental catalysis, motivated by the ambition to realize low-pressure drops at high flow rates for gas-phase reactants. Monoliths are the state-of-the-art reactors in these applications. 

The use of CeOs-based materials in catalysis has attracted considerable attention in recent years, particularly in applications like environmental catalysis, where ceria has shown great potential. This book critically reviews the most recent advances in the field, with the focus on both fundamental and applied issues. The first few chapters cover structural and chemical properties of ceria and related materials, i.e. phase stability, reduction behaviour, synthesis, interaction with probe molecules (CO. O2, NO), and metal-support interaction — all presented from the viewpoint of catalytic applications. The use of computational techniques and ceria surfaces and films for model catalytic studies are also reviewed. The second part of the book provides a critical evaluation of the role of ceria in the most important catalytic processes three-way catalysis, catalytic wet oxidation and fluid catalytic cracking. Other topics include oxidation-combustion catalysts, electrocatalysis and the use of cerium catalysts/additives in diesel soot abatement technology. 

Catalysis by zeolites is a rapidly expanding field. Beside their use in acid catalyzed conversions, several additional areas can be identified today which give rise to new catalytic applications of zeolites. Pertinent examples are oxidation and base catalysis on zeolites and related molecular sieves, the use of zeolites for the immobilization of catalytically active guests (i.e., ship-in-the-bottle complexes, chiral guests, enzymes), applications in environmental protection and the development of catalytic zeolite membranes. Selected examples to illustrate these interesting developments are presented and discussed in the paper. 

The major activities in the science and application of zeolite catalysts are still observed in the field of (shape selective) acid catalysis. However, additional thrust areas can be clearly identified today, viz. zeolites in oxidation or base catalysis, applications in environmental protection, catalysis by ship-in-the-bottle complexes, to enumerate just a few. Many aspects of zeolite catalysis have been covered in a number of recent review articles [e g., 1-6] including the potential catalytic applications of ultra-large pore molecular sieves [7]. Hence there is no real need, nor would it be feasible on the limited number of pages allotted to this review, to cover every aspect fi om the huge amount of work done recently in the field. Rather, the authors restricted themselves to selected topics in catalysis by zeolites which, in their own view, deserve particular attention in the years to come. 

Dr Galwey has spent periods of study leave in England, Italy and South Africa and has presented Invited Lectures at many International Conferences. His interests in solid state chemistry continue, in spite of his retirement, and include applications in environmental protection, the geology of mineral formation and heterogeneous catalysis. 

The photocatalytic degradation of various types of dyes appears to be another prominent and extensively explored application of nanocrystalline Ti02 in environmental catalysis [417-423],... 

In the preceding sections an overwiev is given of the application of catalysts in environmental technology, focusing on stationary sources. This last section overviews new developments in environmental catalysis and the challenges for fundamental... 

This chapter deals with the preparation of multimetallic nanoparticles based on the results of the chemistry of redox processes appUed in catalysis and catalyst preparation [1-4]. First, the general aspects of this technique will be briefly described the second part will be devoted to the practical aspects of this preparation method and then some applications of the resulting catalysts in the synthesis of organic chemicals, in environmental catalysis and in catalysis for energy will be presented. 

For many years, honeycomb monoliths have been the standard catalyst shape in most applications of environmental catalysis. On the other hand, exploration of... 

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