Collect. Czech. Chem. Commun. 1979, 44, 502-507

The effect of the content of sulphonic acid groups of an ion exchanger upon its catalytic activity

Karel Setínek

Institute of Chemical Process Fundamentals, Czechoslovak Academy of Sciences, 165 02 Prague 6-Suchdol


Measurements of the initial reaction rates of the gas and liquid phase reesterification of ethyl acetate by 1-propanol catalyzed by an acid ion exchanger showed that the gradual neutralization of the acid groups by alkali metal ions in aqueous medium decreases uniformly their concentration within the whole mass of the catalyst, which reflects in the gradual decrease in the catalytic activity. On varying the content of sulphonic acid groups by sulphonation of the starting copolymer to a different degree, the ion exchangers possessing fully sulphonated surface layer of different thickness are formed which exhibit the same catalytic activity. The decrease in the activity has been observed only after the sulphonation degree was less than 50 per cent.