“…As mentioned above,although the introduction of athird branch led to the formation of embedded 3D mesopores, mesopores were mainly generated by blocking the crystal growth along the b-axis,e xposing the a-c plane,w hereas almost no mesopores formed by disrupting the growth of the MFI zeolite along the other axis.T hus,t he fifth question is how to open mesopores along the a-axis.T he strategy was to introduce al arger hydrophobic center along with triply branched bis(quaternary ammonium)-containing head groups,a nd stabilize the micelles with decreasing binding energy and facilitate the formation of mesopores along the aaxis.T he results showed that as ingle-crystalline mesoporous MFI zeolite (SCMMZ) with sheetlike mesopores layered along the a-a nd b-axes was synthesized by using triply branched 1,3,5-triphenylbenzene,h aving bis(quaternary ammonium)-containing amphiphilic molecules,with aformula of C 6 H 3 [C 6 H 4 -O-C 6 H 12 -N + (CH 3 ) 2 -C 6 H 12 -N + (CH 3 ) 2 -C 6 H 13 ·-(2 Br À )] 3 (denoted TPB-6). [16] TEM images taken along the [010] direction of the MFI zeolite (Figures 7a,c) show sheetlike mesopores stacking along the a-axis with al ength of about 5-50 nm. The corresponding SAED pattern (Figure 7b)reveals the formation of asingle-crystalline mesostructured MFI.…”