CRYSTAL GROWTH & DESIGN
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2017
·
IF 4.055
Yang Zhao,Zhaoqi Ye,Lei Wang,Hongbin Zhang,Fangqi Xue,Songhai Xie,Xiao-Ming Cao,Yahong Zhang,Yi Tang
Constructing superstructured crystalline materials by crystal engineering is an attractive objective for miscellaneous fields of researchers spanning biomimetics to catalytic materials. Zeolite is a kind of important crystalline catalyst, and superstructured zeolite has great potential for widespread applications. However, the ambiguous crystallization mechanisms hamper the effective and scientific fabrication of superstructured zeolite with exceptional properties. Herein, a fractal superstructured MTW zeolite with mesocrystal side branches is prepared via a nanoparticle-based nonclassical pathway with twinning-plane induced crystallization, which is distinct from the formation of general mesocrystal via crystal–crystal oriented attachment. Deformed atomic connection at a specific crystallographic plane contributes to the production of side branches. Moreover, this intriguing morphology could be regulated merely via adjusting the crystallization kinetics based on the unequivocal nonclassical crystallization mechanism. It will open a new avenue for design and synthesis of targeted crystals with superstructure and extraordinary properties.
研究领域:
材料科学
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催化材料
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晶体工程
✓ 已验证
DOI
高影响因子
Catalysts
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2024
·Vol. 14
·期 12
·925
·
IF 3.8
Guanyu Qie,Miao Zhai,Kake Zhu,Xuedong Zhu
The development of hierarchically structured zeolites to mitigate diffusion limitations and improve catalytic performance constitutes a focus of current research. In this study, we present the synthesis of hierarchical disk-shapedMTWzeolite (ZSM-12-P) with shortened channel length using polycation [-C5H9N+C10H10N+C5H9-C3H6-]n[Br−]2n(PDIP) as an organic structure-directing agent (OSDA). The ZSM-12-P zeolite forms disk-shaped structures with thicknesses ranging from 140 to 160 nm and exhibits rotational intergrowth. These structures are composed of interconnected nanocrystalline domains that form mesopores accessible from the outer surface, while the microporous channels extend along the thickness direction. In addition, the polycationic OSDA possesses strong interaction with framework andMTWstructure-directing ability, enabling the successful synthesis of the Al-rich ZSM-12-P. Owing to its strong acidity and improved diffusion property, the Pt/HZSM-12-P catalyst demonstrates enhanced catalyticn-dodecane hydroisomerization activity and isomer yield.
研究领域:
催化化学
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材料科学
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石油化工
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
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2021
·
IF 5.706
Lei Chen,Wenxia Zhuang,Jingmin Lan,Xiaoling Liu,Shi Jiang,Lei Wang,Yu Zhou,Jun Wang
Mg-bearing MTW silicalite zeolite, MgSi-ZSM-12, was straightforwardly synthesized by involving an unusual acidic pre-gelation system and engaged as the task-specific support for loading the Au nanoparticles (NPs). The resulting Au/MgSi-ZSM-12 catalyst showed stably excellent activity for the oxidation of HMF into FDCA in the presence of atmospheric dioxygen (O 2 ) without externally adding any liquid base, affording a yield of 87 % and turnover number (TON) of 331 based on the surface Au sites. Superior basicity was evidenced by embedding Mg species into the all-silica zeolitic skeleton, which enables strong, weak, and near-zero affinity towards aldehyde, alcohol, and carboxyl groups, respectively, thus, allows rapid and high-uptake adsorption of HMF, but negligible adsorption of FDCA. This unique feature of the Mg-bearing all-silica zeolite support together with its synergy with the active sites of Au NPs is revealed to accelerate the production of FDCA under the base-free mild condition.
研究领域:
催化化学
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材料科学
·
环境化学
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2022
·
IF 5.876
Jinhao Du,Ruting Yuan,Feng Lin,Lijun Liao,Ge Yang,Furong Tao,Yuezhi Cui,Christine E.A. Kirschhock
Azonia-spiro compounds have been reported as organic templates for synthesizing many extra-large pore high silica zeolites , often isomorphically substituted by germanium . However, these templates are usually obtained in the presence of sodium hydroxide, leading to persisting sodium ions in the final products. Sodium cations may compete with azonia-spiro organics as templates during zeolite synthesis. Therefore, effect of any residual sodium cations on the synthesis results needs to be investigated. This work documents the effect of sodium ions on zeolite formation using four structurally similar azonia-spiro compounds as templates. Different silicogermanate zeolites (UTL, an unknown zeolitic phase, etc.) were formed in the absence of sodium cations. Notably, the syntheses of silicogermanate UTL and siliceous MTW zeolites using azonia-spiro[4,6] and [6,6] are reported for the first time. Controlled amounts of sodium chloride were added to zeolite crystallization mixtures without residual sodium hydroxide. In the presence of 0.005–0.1 mol/L Na + , silicogermanate zeolites were the dominant phases. Further increasing the Na + concentration to 0.152 and 0.317 mol/L, formation of UTL and an unknown silicogermanate phase were inhibited in favor of a dense sodiumgermanate (Na 4 Ge 9 O 20 ). Moreover, sodium ions next to azonia-spiro organic templates also influence the morphologies of the MTW zeolites. The observed high sensitivity of zeolite formation in the presence of even traces of sodium therefore has impact on synthesis protocols of large pore silicogermanate zeolites. This work highlights how small, often overlooked, factors in inorganic material synthesis can drastically change the outcome.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
RSC Advances
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2017
·Vol. 7
·期 38
·23272-23278
·
IF 3.108
Peicheng Wang,Yang Zhao,Hongbin Zhang,Tao Yu,Yahong Zhang,Yi Tang
A series of diquaternary pyrazolium-derived organic templates (N,N′-dimethyl-N,N′-1,6-dihexylidenedipyrazolium, N,N′-diethyl-N,N′-1,6-dihexylidenedipyrazolium, N,N′-dipropyl-N,N′-1,6-dihexylidenedipyrazolium, denoted as 6C-DMP, 6C-DEP, 6C-DPP, respectively) with methyl, ethyl and propyl groups substituted on the N atom of pyrazole ring at both terminals have been used in the synthesis of high silica MTW and MFI zeolites. Through combining the characterization results, including XRD, NMR, elemental analysis, TG, XRF, FE-SEM, N2 sorption and FE-TEM, with molecular mechanics simulations to explore the location, orientation and the interaction energies of the three templates, we confirmed the state of templates in zeolite framework, carefully characterized their morphology/structure properties, and finally investigated their different spatial effects for the zeolite formation. The study found that 6C-DMP and 6C-DEP are able to produce MTW, while 6C-DPP is able to produce MFI. 6C-DMP, owing to a good match with the MTW framework and can be used to synthesize regular MTW zeolite with few defects. The MTW zeolite prepared by using 6C-DEP as a template presents more defects and irregular macromorphology due to a relatively poor match to the MTW framework. 6C-DPP can get MFI other than MTW due to a larger spatial hindrance, and it is located in the MFI framework with a special spatial orientation.
研究领域:
化学
·
材料科学
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物理化学
✓ 已验证
产品关联
DOI
高影响因子
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