Tailored mesoporosity

Figure 2.7 Schematic representation of the partial detem-plation and desilication treatment to tailor mesoporosity development in zeolite crystals.

By judicious choice of the precursor and also careful control of both carbonization and activation steps, it is possible to tailor the pore structure for particular applications (e.g.. Barton et al., 1999). Mesoporosity (near or larger than 30 A) is desirable for liquid-phase applications, whereas smaller pore sizes (10 to 25 A) are required for gas-phase applications (Yang, 1997). The following table (Table 1) shows the pore size distribution as a function of the rank of the precursor coal (Wilson, 1981). 

Preparation and dynamic adsorption properties of activated carbons with tailored micro- and mesoporosity... 

Using the self-formation phenomenon to fabricate hierarchically meso-mac-roporous binary mixed oxides, the mesoporosity and macroporosity can be tailored by tuning contents of the chemical components. Furthermore, the use of mixed alkoxide solutions and surfactants allows for the formation of binary metal oxide materials with structural properties of large multiporosity and high specific siuface area. Such modulable monolithic materials with multiscaled pore sizes and a wide variety of chemical compositions should be promising for multiple apphcations in catalysis and separation technology. 

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