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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. The scheme of isomorphously substituted method of introducing P into ZSM‐5 framework and catalytic performance over H[P, Al]‐ZSM‐5 and H[P, Al]‐ZSM‐5‐AT‐0.05 M in coupling methanol with 1‐butene. P substituted HZSM‐5 is treated with NaOH solution to form mesoporous zeolites. The result shows that H[P, Al]‐ZSM‐5‐AT‐0.05 M exhibited higher catalytic stability, higher apparent reaction rate, effectiveness factor and lower content of diffusion limitation in coupling of methanol with 1‐butene to propylene reaction. [ABSTRACT FROM AUTHOR]

Catalytic performance is influenced by the morphology and assembly of catalyst particles. Therefore, Zn ion‐doped HZSM‐5 zeolite with different morphological structures is prepared using post‐treatments of selective dissolution and recrystallization, causing silicon components to migrate from the interior to the exterior in the different template etching processes. The core–shell, hollow, and hierarchical core–shell Zn/HZSM‐5 microspheres with weak acid sites on the external surfaces are successfully synthesized. Hierarchical core–shell‐structured Zn/HZSM‐5 microspheres with a silicon‐rich surface layer are prepared using an etching method in n‐butylamine solution. Their catalytic activity is investigated in methanol aromatization. The functionalized morphological Zn/HZSM‐5 catalysts show good catalytic performance and the silicon‐rich surface layer improves selectivity of p‐xylene in the reaction of methanol to aromatics. Three morphological structured zeolite synthesis routes for p‐xylene are reported and selectivity is studied. Zn/HZSM‐5Si shows lower activity in the conversion of methanol to aromatics, but higher selectivity to xylene (particularly p‐xylene) considering benzene, toluene, and xylene. The Zn/HZSM‐5 catalysts treated in tetrapropylammonium hydroxide (TAPOH) and n‐butylamine solution exhibit excellent catalytic activity and stability in MTA reactions. [ABSTRACT FROM AUTHOR]

Nano‐grains on the surface region of the DZ125 directionally solidified nickel based superalloy is obtained through burnishing processing at both room and low temperature. Compared to the low temperature burnished (LTB) specimen, the {111}/[112] type nano‐twins are generated on the room temperature burnished specimen (specimen RTB). The results demonstrate that the nano‐grains could improve the corrosion resistance and promote the formation of compact corrosion product films on the burnished DZ125 alloy surface in a 3.5 wt% NaCl solution. The combined effects of local deformation nano‐twins and lower percentage of Cr2O3 in corrosion product film lead to the fact that the specimen RTB exhibits a relatively lower corrosion resistance compared to the specimen LTB. Nano‐grains are fabricated on the surface of DZ125 superalloy in this work. {111}/[112] type nano‐twins are found in room temperature burnished DZ125 superalloy. The corrosion resistance of DZ125 alloy is improved significantly after surface nanocrystallization. Nano‐grains without deformation nano‐twins induce the best corrosion resistance for DZ125 alloy. [ABSTRACT FROM AUTHOR]