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Porosity effects mesoporosity

In view of catalytic potential applications, there is a need for a convenient means of characterization of the porosity of new catalyst materials in order to quickly target the potential industrial catalytic applications of the studied catalysts. The use of model test reactions is a characterization tool of first choice, since this method has been very successful with zeolites where it precisely reflects shape-selectivity effects imposed by the porous structure of tested materials. Adsorption of probe molecules is another attractive approach. Both types of approaches will be presented in this work. The methodology developed in this work on zeolites Beta, USY and silica-alumina may be appropriate for determination of accessible mesoporosity in other types of dealuminated zeolites as well as in hierarchical materials presenting combinations of various types of pores. [Pg.217]

In this work we have studied the effect of catalyst porosity on regeneration efficiency of FCC catalyst and shown that index of mesoporosity can very well explain the regeneration efficiency of FCC catalysts. We have also shown how different Pore Regulating Agents(PRA) can be used in catalyst formulation to create a desirable mesopore range of size distribution of FCC catalyst. [Pg.271]

An effective use of activated carbon requires a knowledge about the stmcture of its porosity, obtained from equilibrium data, namely the pore-size distributions of the microporosity in particular, of the pore-size distributions of the mesoporosity, of the composition of the carbon surfaces onto which adsorption occurs, and knowledge of the dynamics of adsorption to indicate its effectiveness in industrial use. [Pg.539]

When calcium is used in the preparation of activated carbons it is found that the adsorption capacity increases in both carbon series with the extent of burn-off. However changes in the porosity of the activated carbons with burn-off differ considerably in the presence of calcium, mainly for CO, activation. Figure 1 (a and b) for carbon A and Figure 2 (a and b) for carbon B show the remarkable effect of the catalyzed carbon-CO, activation. The adsorption isotherms shapes are very different from those found for the uncatalyzed activation. Isotherms are a combination of type I and II in contrast to the well defined type I isotherms obtained for the uncatalyzed CO, activation. Carbon A2 and B2 behave differently (Figure 1 b and 2b) probably due to their different initial porosity and calcium contents. In any case, catalytic activation in CO, gives rise to a noticeable development of mesoporosity and, as a result, a much wider pore size distribution. Mercury porosimetry. Figure 3 (a and b), show the very different pore size distributions obtained by catalytic activation with calcium mesoporosity development is very noticeable in agreement with the N, adsorption data. [Pg.373]


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See also in sourсe #XX -- [ Pg.145 , Pg.198 ]




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Mesoporosity

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