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].