Storage, cleaned surfaces active

The enormous importance of carbon in such diverse fields as inorganic and organic chemistry and biology is well known however, only the aspects of carbon relevant to catalysis will be described here. The main topics we are concerned with are porous activated carbons, carbon black as catalyst supports and forms of coking. Carbon is also currently used as storage for natural gas and to clean up radioactive contamination. Carbon is available at low cost and a vast literature exists on its uses. Coal-derived carbon is made from biomass, wood or fossil plants and its microstructure differs from carbon made from industrial coke. Activated carbons are synthesized by thermal activation or by chemical activation to provide desirable properties like high surface area. 

Ceria and alumina, which form the intermediate porous layer (the washcoat) between the mechanical support and the supported metals and promotors, are important components in three-way catalysts (TWC) used for car exhaust gas cleaning. Although basie studies have been published on such systems [1], the interactions which can exist between alumina and eeria and which in turn may affect the interactions between the supported metal and the washcoat [2], are not fully understood. In particular, the multiple roles attributed to ceria, like stabilization of the alumina [3], of the supported metals [4], like storage and release of oxygen [2], are veiy probably dependent on preparation methods, activation and reaction conditions. Therefore, selective characterization of each oxide in ceria-alumina can be useful for a better imderstanding of the role played by both alumina and ceria in TWC. The present work describes two "ehemical methods", the adsorption of carbon dioxide followed by IR spectroseopy and the temperature-progranuned reduction (TPR), which lead to an estimation of the surface extent of alumina and ceria respectively. 

Active storage environments are those where the contaminants are continually removed from the storage environment. Preferential hydrocarbon adsorption can be on freshly oxidized aluminum or activated carbon. Hydrocarbon contaminants can be continually removed by having an oxidizing atmosphere to react with the hydrocarbons to form CO and CO2. A UV/O3 cleaning cabinet provides such an environment. The UV/O3 cleaning chamber is excellent for storing surfaces where surface oxidation is not a problem. 

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