6533b852fe1ef96bd12aaaff

RESEARCH PRODUCT

Surface acidity studies on active aluminas by means of the amine titration method and heterogeneous isotopic exchange using HTO

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Abstract The maximum sorption capacity of n-butylamine (A + n-but ), the exchange capacity of HTO (A HTO ) and the acid strength distribution (ASD) - titration of n-butylamine using arylmethanols as indicators - were measured for a series of commercial active aluminas. A + n-but was formally regarded as total acidity and was found to be larger than A HTO , the latter representing a measure of the Broensted acidity. On the other hand, the cumulative acidity derived from ASD gave values smaller or equal to A HTO . Changes in A HTO and A + n-but within a series of aluminas manufactured at different calcination temperatures gave the expected results which were also supported by infrared spectroscopic measurements. The calcination temperature during the manufacturing process was also shown to have a distinct influence on the ASD. Differences in the ASD of aluminas are discussed.