کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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67580 | 48488 | 2007 | 9 صفحه PDF | دانلود رایگان |
MCM-22 zeolites with different Si/Al ratios were dynamically synthesized through hydrothermal method, and the Pd/MCM-22 catalysts were prepared by ion-exchange method as well. The physicochemical properties of the samples were well characterized by XRD, SEM, TEM, N2 adsorption, NH3-TPD, and FT-IR of d3-acetonitrile adsorption. MCM-22 synthesized was markedly different from those in previous literatures, showing much smaller crystals. MCM-22 with Si/Al ratio of 25 showed the highest crystallinity and concentration of Brønsted acid sites. The loading of Pd particles had little influence on the structural and porous properties of MCM-22 zeolite. The specific surface area, pore volume, pore diameter, and the concentrations of the acid sites all decreased with increasing Pd loading as expected. One-step synthesis of methyl isobutyl ketone from acetone was investigated over Pd/MCM-22 catalysts. An acetone conversion of 34.0% and a selectivity of 86.9% for MIBK were realized. The catalytic results also suggested that a proper balance between metallic and acidic sites was necessary for obtaining high catalytic performance.
Pd/MCM-22 catalysts were prepared by ion-exchange method. The catalysts showed high catalytic activity, reaching a conversion of 34.0% and a selectivity of 86.9% to MIBK. The results also indicated that a proper balance between metallic and acidic sites was necessary for obtaining high catalytic activity.Figure optionsDownload as PowerPoint slide
Journal: Journal of Molecular Catalysis A: Chemical - Volume 272, Issues 1–2, 2 July 2007, Pages 75–83