Activation highly loaded

Loaded Adsorbents. Where highly efficient removal of a trace impurity is required it is sometimes effective to use an adsorbent preloaded with a reactant rather than rely on the forces of adsorption. Examples include the use of 2eohtes preloaded with bromine to trap traces of olefins as their more easily condensible bromides 2eohtes preloaded with iodine to trap mercury vapor, and activated carbon loaded with cupric chloride for removal of mercaptans. 

Porosity and Pore Size. The support porosity is the volume of the support occupied by void space and usually is described in units of cm /g. This value represents the maximum amount of Hquid that may be absorbed into the pore stmcture, which is an especially important consideration for deposition of metal salts or other active materials on the support surface by Hquid impregnation techniques. The concentration of active material to be used in the impregnating solution is deterrnined by the support porosity and the desired level of active material loading on the catalyst. If the porosity is too low, inefficient use of the support material and reactor volume may result. If the porosity is too high, the support body may not contain sufficient soHd material to provide the strength necessary to survive catalyst manufacture and handling. 

The support materials for the stationary phase can be relatively inactive supports, e.g. glass beads, or adsorbents similar to those used in LSC. It is important, however, that the support surface should not interact with the solute, as this can result in a mixed mechanism (partition and adsorption) rather than true partition. This complicates the chromatographic process and may give non-reproducible separations. For this reason, high loadings of liquid phase are required to cover the active sites when using high surface area porous adsorbents. 

SCR systems at stationary diesel engines profit from the high exhaust gas temperatures of about 350-400 C, caused by the usually constant high load operation conditions of the diesel engine. In this temperature window nearly all known SCR catalysts are very active. Moreover, weight and size of the exhaust gas catalyst are usually not strictly limited, which results in a good NO, reduction efficiency (DeNOJ. However, DeNO, is not the only criterion for an SCR catalyst. Further requirements are excellent selectivities regarding NO and urea/ammonia as well as low ammonia slip, which is an undesired secondary emission of the SCR process. Therefore, all SCR catalysts exhibit surface acidity, which is necessary to store ammonia on the catalyst surface and, thus, to prevent ammonia slip. 

Shamaila, S., Sajjad, A.K.L., Chen, F., and Zhang, J. (2010) Study on highly visible light active Bi203 loaded ordered mesoporous titania. Applied Catalysis B Environmental, 94 (3—4), 272—280. 

Silicates are semi-active fillers which, even at high loading, give soft and elastic vulcanisates. 

It was also found that the specific catalytic activity (TOF) could be maintained at a high value over a wide range (0.5-9% wt) of ruthenium loading. The independence of activity from catalyst loading was attributed to the high dispersion of deposited ruthenium-hydrated oxide in the catalysts with high loading, which was confirmed by the microscopy studies. 

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