Ef. Sousa-aguiar et al., Influence of the external surface area of small crystallite zeolites on the micropore volume determination, MICROP M M, 25(1-3), 1998, pp. 185-192
The micropore volumes of zeolites displaying different external surface are
as were determined with the help of two classical methods: the Dubinin-Radu
shkevich (DR) and t-plot. The results were compared with a new approach, in
which adsorption isotherms are decomposed into two adsorption areas: one c
orresponding to the micropore filling and described by the DR equation, and
the other ascribed to adsorption on the external surface and ruled by the
classical BET equation. The results indicate that the proposed model fits t
he experimental data very well. Furthermore, the DR-plot seems to overestim
ate micropore volume, whereas the t-plot, in the range 6<t<9 Angstrom, unde
restimates it. (C) 1998 Elsevier Science B.V. All rights reserved.