文献类型：期刊文献

英文题名：Fabricating ZSM-23 with reduced aspect ratio through ball-milling and recrystallization: Synthesis, structure and catalytic performance in N-heptane hydroisomerization

作者：Zhai, Miao[1]; Li, Liyuan[2]; Ba, Yulei[1]; Zhu, Kake[1]; Zhou, Xinggui[1]

机构：[1] UNILAB, State Key Laboratory of Chemical Engineering, Shanghai Key Laboratory of Multiphase Materials Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China; [2] Sinopec, Shanghai Research Institute of Petrochemical Technology, 1658 Pudong North Road, Shanghai, 201208, China

年份：2019

卷号：329

起止页码：82

外文期刊名：Catalysis Today

收录：EI(收录号：20184906177884)

语种：英文

外文关键词：Ammonia - Crystallinity - Grain size and shape - Heptane - Sodium compounds - Diffusion - Isomerization - Recrystallization (metallurgy) - Crystal structure - Hexane - Milling (machining) - Catalyst selectivity - Zeolites

摘要：Unidimensional zeolites often form rod-shaped crystals that suffer from low catalytic selectivity or catalyst lifetime owing to their poor diffusion properties. Combined postsynthetic ball-milling and recrystallization methods were investigated to produce unidimensional ZSM-23 crystals with reduced aspect ratio. The influences of ball-milling in the presence/absence of structure directing agent (SDA) and diverse recrystallization media, including H2O, Na2Si3O7 solution, synthetic mixture and mother liquor, over crystallinity, crystal size, textural properties as well as acidity, were intensively explored using characterization techniques such as XRD, SEM, N2 physisorption, 27Al MAS NMR, NH3-TPD, pyridine IR spectroscopy and diffusion measurement. The results showed that crystal size of ZSM-23 was considerably reduced after ball-milling treatment, however, at the expense of crystallinity, acidity and porosity. Recrystallization in the presence of mother liquor was identified as the most effective and economic way to restore crystallinity. The optimized ZSM-23-M-m sample derived from ball-milling in the presence of SDA and a subsequent recrystallization in separated synthesis mother liquor exhibited higher isomer yield (ca. 53%) than the parent sample (ca. 34%) in n-heptane hydroisomerization reaction owing to the enhanced diffusion property and regained acidity after recrystallization. ? 2018 Elsevier B.V.