Synthesis of Hierarchically Porous H[P, Al]‐ZSM‐5 and its Catalytic Performance in Coupling Transformation of Methanol with 1‐Butene

Abstract

Hierarchically porous P substituted HZSM‐5 (H[P, Al]‐ZSM‐5‐AT‐0.05 M ) was successfully synthesized by isomorphous substitution method with introduced P atoms into ZSM‐5 zeolite frameworks followed by alkali treatment. H[P, Al]‐ZSM‐5‐AT‐0.05 M was characterized by XRD, ICP‐OES, SEM, FT‐IR, N2 adsorption‐desorption, NH3‐TPD, XPS, Py‐IR, and TG‐DTA, respectively. The surface area, pore volume, particle size and P/Al (molar ratio) are 328 m2.g−1, 0.23 cm3.g−1, 563 nm and 0.027, respectively. The catalytic performance of H[P, Al]‐ZSM‐5‐AT‐0.05 M in coupling reaction of methanol with 1‐butene was investigated in the fixed‐bed reactor. On the condition of reaction temperature at 500°C under atmosphere pressure, the main product is propylene with the selectivity and yield of 33.7% and 31.0%, respectively. Hydrogen transfer index was calculated to 0.24. Moreover, its diffusion limitation was investigated with the self‐etherification of benzyl alcohol reaction. The value of Thiele modulus (η ) and effectiveness factor (ϕ ) are 0.08 and 16.9, respectively.

Hierarchically Structured Zeolites: From Design to Application

“…In contrast to the synthesis strategies discussed above, additional porosity can also be created within zeolites by postsynthesis treatment of zeolite crystals that leads to the formation of secondary meso-macropores. − Generally, the postsynthesis treatments of previously formed zeolites consist of demetalation (extraction of framework atoms) or delamination, which are realized by steam, − acid, ,− base, − ,− or fluoride treatments ,− or more refined approaches such as swelling, − exfoliating, , or interlayer pillaring with amorphous silica. …”