Fig. 6. SEM images and particle size distributions of (a)
ZSM-5-RD, (b) ZSM-5-RS, (c) ZSM-5-SD, (d) ZSM-5-SS.
The textural properties of four ZSM-5 samples are summarized in Table 1.
The N2 adsorption-desorption isotherms of ZSM-5 samples
obtained via RPB premix differ from those by STR (Fig. 7). Besides the
steep uptake below P/P 0 = 0.02 in the isotherms
of all samples (indicating uniform microporous in ZSM-5 zeolites), there
is an H4 hysteresis loop of the ZSM-5 samples obtained via RPB premix
when P/P 0 is 0.45, which indicates the presence
of slit-shaped mesoporous structures [42]. The textural properties
in Table 1 reveal that the surface areas and pore volumes of ZSM-5
samples obtained via RPB premix are higher than those via STR premix.
And the mesoporous characters are generated accompanied by the decrease
of microporous structures [43].