<2 nm) and cylindrical pore model (pore diameter >2 nm)” from Quantachrome
data reduction software.
From Fig. 15 can be seen that the NLDFT method predicts a micropore modal
size of 0.87 nm (similar to the recently reported by Orsikowsky-Sanchez et al. [52])
and can be related with the windows of the cavity, while CY correctly estimates the
theoretical size of the internal cavity (1.14 nm). Orsikowsky-Sanchez et al. [52]
considered that the value obtained is an intermediate size between the windows and
cages. This example is to address the care that must be taken into the application of
the different methods to obtain the PSD.
Fig. 14 Micropore size
distributions with HK, SF,
and CY methods for 5A and
FAU zeolites. The structures
shown in each PSD
correspond to each zeolite,
indicating the sizes of
cavities (blue) and windows
(red)
Fig. 15 Micropore size
distributions of Zeolite 5A
using CY and NLDFT
methods
50
J. Villarroel-Rocha et al.