*2.2.1 X-ray diffraction (XRD)*

**Figure 1** shows X-ray diffraction (XRD) patterns of various hierarchical ZSM-5 samples. As-synthesized NaZSM-5 exhibited the characteristic peaks associated with MFI framework [15]. It indicates that MFI-structured zeolites were successfully synthesized. XRD pattern of HZSM-5 shows that ZSM-5 h zeolite structure was preserved after post-synthesis treatment on NaZSM-5 h through NH4 + exchange process followed by calcination at 823 K.
