Ceramic catalysts

On crystallisa tion from aqueous solution, the dihydrate is generally obtained. The tungstates are of particular interest in electronic and optical appHcations, but are also used for ceramics, catalysts, pigments, corrosion, and as fire inhibitors, etc. 

Gulati, S.T., Makkee, M., and Setiabudi, A. (2006) Ceramic catalysts, supports and filters for diesel exhaust aftertreatment, in Structured Catalysts and Reactors, 2nd edn. Chapter 19 (eds A. Cybulski and J.A. Moulijn), CRC Taylor Francis, Boca Raton, p. 663. 

Aluminum is produced commercially by the electrolysis of cryolite, Na3AlF6, but bauxite, A1203, is the usual naturally occurring source of the metal. The oxide is a widely used catalyst which has surface sites that function as a Lewis acid. A form of the oxide known as activated alumina has the ability to adsorb gases and effectively remove them. Other uses of the oxide include ceramics, catalysts, polishing compounds, abrasives, and electrical insulators. 

Fig. 5. Absorption and desorption kinetics for MgH2 with ceramic catalyst addition at 300°C.

Figure 5 shows the absorption and desorption kinetics of nanocrystalline MgH2 with ceramic catalysts at 300°C. The BCN catalyst addition was very effective to enhance the desorption kinetics in comparison to pure MgH2 and SDC added composite. 

Table 1. Absorption and desorption kinetics of MgH2 with ceramic catalysts at 300°C.

Using higher-quality catalysts will lead in increased process efficiency while the required frequency of catalyst replacement can be reduced. Similarly, the replacement of ceramic catalyst support with activated alumina supports presents the opportunity for recycling the activated alumina supports with the spent alumina catalyst. 

Gulati ST. Ceramic catalyst supports for gasoline fuel. In Cybulski, A Moulijn JA, eds. Structured Catalysts and Reactors. New York Marcel Dekker, 1998 15-58. 

L. (1998) Preparation and characterization of extruded monolithic ceramic catalysts. Catal. Today, 41, 87. 

Chemical substances are materials which can be produced or used in chemical processes. Chemical processes include such reactions as combustion. Since the rise of the modem chemical industry in the nineteenth century, numerous chemical substances have been developed and created including acids, bases, fertilizers, ceramics, catalysts, dyestuffs, fabrics, explosives, paints, plastics, petrochemicals, pharmaceuticals, agricultural chemicals, specialty chemicals, automotive materials, and home and commercial electronics components. 

Yttrium 39 Y High-temperature alloys, metallurgy, red phosphor, optical glasses, ceramics, catalysts, lasers, microwave devices... 

As stable materials, just like brick, ceramics have excellent durabiUty against water. The ceramic catalysts were tested in the esterification of n-octanoic acid with methanol to methyl n-octanoate to determine their stabihty to the water Hberated. 

Monodispersely-sized submircon zirconia colloids are useful starting material for ceramics, catalysts, and chromatographic stationary phases. One such process (polymerization-induced colloid aggregation or PICA process) requires entirely reproducible aqueous zirconia sols with no surfactants [1,2]. In the PICA process developed by Her and McQueston [3], the concentrated ( 20 wt %) 100 nm zirconia colloids are aggregated by urea-formaldehyde polymerization reaction to produce the porous zirconia particles in the size range of 4 - 6 pm [1,2],... 

A mixture of carbon monoxide, hydrogen, and carbon dioxide is produced by steam reforming, a process in which natural gas and steam are mixed and reacted in a reformer operated at 1.6 MPa. Natural gas may be assumed to consist entirely of methane (CH4), although other compounds may be present in small concentrations. In the present process, steam and natural gas are fed to the reformer in a ratio of 3.0 moles of steam per mole of methane. The reformer consists of an arrangement of vertical tubes filled with nickel-impregnated ceramic catalyst. Rows of these tubes are located inside an insulated firebox, where they are heated by the combustion of natural gas. 

Inorganic powders play a key role in many fields—ceramics, catalysts, medicines, food, etc.— and many papers and books discuss powder preparation. Powder preparation is a very important step in the processing of ceramics. Table 1.1 presents the methods used for preparing fine ceramic powders. ... 

Figure 13 shows the forces acting on a circular ceramic catalyst support under operating conditions. The holding pressure must be high enough that the frictional force. 

---