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Hierarchical ZSM‐5 zeolites were synthesized by in‐situ crystallization of mesoporous carbon‐silica composites with a well‐ordered SBA‐15 structure. The hierarchical ZSM‐5 zeolite possessed a rather high external surface area (205 m2/g) and pore volume (0.35 cm3/g) compared with the reference ZSM‐5 zeolite, as well as higher acid‐site accessibility to large molecules. In the naphthalene benzylation reaction, the hierarchical HZSM‐5 zeolite converted approximate 50 % of benzyl chloride in 100 minutes under mild conditions and showed a high stability, which could be ascribed to the improved diffusion ability and acid‐site accessibility. [ABSTRACT FROM AUTHOR]

• A hierarchical zeolite Beta with self-assembled morphology of nanosized crystallines. • Nanosized crystallites aggregated by10–50 nm result from addition of GO. • Admirable connectivity of mesopores in the zeolite materials. • High hierarchical factor with high external surface area and mesoporous volume. Hierarchical zeolite Beta has been successfully synthesized by adding graphene oxide (GO) in the hydrothermal system and characterized by XRD, SEM and N 2 adsorption-desorption. The results show that the mesoporous distribution of the hierarchical zeolite Beta can be adjusted in the range of 3–7 nm and the mesoporosity can be varied by changing the type and content of GO. The formation of mesoporous structure in the zeolitic particles is from that the growth of crystalline is blocked in part by GO attached onto the zeolitic crystalline surface. Compared to spherical structure of GO nanopowders, laminar structure of GO nanosheets is propitious to increase the connectivity of the mesopores in the zeolite materials. [ABSTRACT FROM AUTHOR]

A series of hierarchical SAPO-34 zeolites with controllable crystallite sizes ranging from 40 to 200 nm and morphologies from well-dispered urtral-small nanocrystals to compact spherical-like polycrystallite aggregates were fabricated by only modulating the Si/TEAOH molar ratios in the gel mixture. [Display omitted] • Hierarchical SAPO-34 zeolites are synthesized without a secondary template. • A possible forming mechanism of SAPO-34 zeolite is proposed. • Crystal sizes and morphologies can be well modulated by controlling Si/TEAOH molar ratios. • The rich mesopore structure resulted from the intercrystal pores of nanoparticles is fabricated. A series of hierarchically porous SAPO-34 zeolites with tunable crystal sizes varying from 40 to 200 nm were synthesized with different morphologies from well-dispersed ultra-small nanocrystals to compact spherical-like polycrystalline aggregates by only changing the Si/TEAOH (TEAOH: tetraethylammonium hydroxide) molar ratios in the gel precursors without using any meso -templates. The hierarchical samples were systematically characterized by XRD, FT-IR, SEM, TEM, XRF, 29Si MAS NMR spectra and N 2 adsorption–desorption. It reveals that hierarchical SAPO-34 nanocrystals with high crystallinities, larger external surface areas (61 – 125 m2/g) and mesopore volumes (0.15 – 0.29 cm3/g) were obtained under current synthesis condition. [ABSTRACT FROM AUTHOR]