Concentration Effects by Specific Adsorption

On ZSM-22, modeling of alkane hydroconversion needed to differentiate between pore, pore mouth and external surface adsorption [82]. The issue 

When in catalysis with functionaKzed molecules unfavorable sorption ratios in the intracrystalline space occur, significant reduction of turnovers is encountered [86]. Therefore, zeolite-catalyzed conversion of reactants with strongly different polarity, remains a challenge [86], though this phenomenon is less of a problem in the gas phase [87]. A number of observations in oxidations with H2O2 over TS-1 have been rationalized in this way [88]. Benign effects on Friedel-Crafts reactions by zeolites in supercritical CO2 [89] are not unexpected as its density is between that of liquid and vapor phase. 

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