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zeolite synthesis FROM A HIGH SI-AL-FLY ASH FROM EAST CHINA

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ZEOLITE SYNTHESIS FROM A HIGH SI-AL-FLY ASH FROM EAST CHINA

Organotemplate-free Hydrothermal synthesis of SUZ-4 zeolite: Influence of synthesis Conditions

中国科学院地质与地球物理研究所2002学术年会

作者： J.C.Umaa X.Querol A.Lopez-Soler F.Plana Instittute of Earth Sciences CSICLluis Sole i Sabaris s/n.08028-Barcelona Spain

A high Al-Si Chinese fly ash from Dou He power plant(Tangshan city,Hebei Province, Eastern China) was selected as starting material of the zeolitization *** material was obtained by conventional alkaline activation by using NaOH and KOH *** synthesis process was optimized by applying a wide ranges of reaction temperature,time and activation agent concentrations.A high solution / fly ash ratio was used in order to allow dissolution of highly resistant Al-Si phases such as *** synthesis yields were obtained by using both KOH and NaOH *** products reached a cation exchange capacity(CEC) up to 2.3 meq *** zeolites obtained with a high CEC were:NaP1,KM and F linde *** low contents of major impurities of this fly ash enhance the potential application for the synthesis of zeolites for waste water treatment.

关键词： fly ash zeolite synthesis coal-fired power plant China

来源： cnki会议评论

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Chinese Journal of Chemical Engineering 2014年第1期22卷 120-126页

作者：周华兰吴雅静张伟王军 State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemistry and Chemical Engineering Nanjing University of Technology College of Sciences Nanjing University of Technology

Various conditions were investigated in detail for the novel organic template-free static hydrothermal synthesis of SUZ-4 zeolite in the presence of seeds. The obtained samples were characterized by XRD （X-ray diffraction）, SEM （scanning electron microscope）, TG （thermal gravimetric analysis）, ICP （inductively coupling plasma） elemental analysis, nitrogen sorption isotherm and surface area. The results show that pure SUZ-4 zeolites with high crystallinity are obtained in a broad window of synthesis conditions： seed mass concentration 0.2%-2%, SIO2/A1203 molar ratio 21 25, KOH/SiO2 molar ratio 0.33 0.43, H20/SiO2 molar ratio 7.14-38.1, aging time 24 h, crystallization temperature 160℃, and crystallization time 6-10 d. Also, crystallinity and size of the rod-like SUZ-4 zeolite crystals are found to alter with the conditions.

关键词： crystal growth microporous materials SUZ-4 zeolite zeolite synthesis organic template-free

Studies on the synthesis, Properties and Preparation Methods of zeolite ZK-4

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Chemical Research in Chinese Universities 2000年第4期16卷 306-312页

作者： ZHAO Zhen-hua and YIN Du-lin (Department of Chemistry, Hunan Normal University, Changsha 410081, P. R. China) 湖南师范大学湖南长沙 410081

A zeolite designated as ZK-4 was synthesized hydrothermally in the system (TMA)2ONa2O-Al2O3- SiO2- H2O at 80 - 100℃ with tetramethylammonium hydroxide as an organic templating agent. The pure zeolite ZK-4 could be prepared by using the mother liquor obtained after filtration as the source of templating agent. The effect of some synthetic conditions such as the amount of tetramethylammonium hydroxide used, n [ (TMA)2O + Na2O] /n (Al2O3) ratio, n (SiO2)/n(Al2O3) ratio and crystallization time, etc. on the crystalline phase of the product was investigated. When the following molar ratios of the reaction mixture, n (SiO2)/n (Al2O3) 4-10, n[(TMA)2O+Na2O]/ n (Al2O3 ) > 7, n (Na2O)/n (Al2O3)=0. 5-2. 0, n (H2O)/ n(A12O3)=80-450, were used, pure zeolite ZK-4 could be obtained. The synthetic products were characterized by X-ray powder diffraction, atomic absorption spectrophotometry (AAS), adsorption measurement, thermogravimetric analysis(TGA), and 29Si magic angle spinning nuclear magnetic resonance technique. zeolite ZK-4 has a higher thermal stability than sodium zeolite A due to higher n(Si)/n(Al) ratio of zeolite ZK-4.

关键词： zeolite ZK-4 Molecular sieve zeolite synthesis Property,Tetramethylammonium hydroxide template

Eco-friendly synthesis of high silica zeolite Y with choline as green and innocent structure-directing agent

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Chinese Journal of Catalysis 2019年第1期40卷 52-59页

作者： Dawei He Danhua Yuan Zhijia Song Yunpeng Xu Zhongmin Liu National Engineering Laboratory for Methanol to Olefins Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina University of Chinese Academy of Sciences Beijing 100049China

zeolite synthesis in contemporary chemical industries is predominantly conducted using organic structure‐directing agents(OSDAs),which are chronically hazardous to humans and the *** is a growing trend to develop an eco‐friendly and nuisanceless OSDA for zeolite ***,choline is employed as a non‐toxic and green OSDA to synthesize high silica Y zeolite with SiO2/Al2O3 ratios of 6.5–*** prepared Y zeolite samples exhibited outstanding(hydro)thermal stability at ultrahigh temperature owing to the higher SiO2/Al2O3 *** XRF,SEM,29Si‐NMR and 13Na+results suggested that choline plays a structure‐directing role in the synthesis of Y zeolite,while the feed molar fraction of Na+is a crucial determinant for the framework SiO2/Al2O3 ratio and the crystal morphology.

关键词： zeolite synthesis FAU zeolite High silica Green organic structure‐directing agent (Hydro)thermal stability

Surface-gel-conversion synthesis of submicron-thick MFI zeolite membranes to expedite shape-selective separation of hexane isomers

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Science China Materials 2021年第2期64卷 374-382页

作者： Huazhen Rong Gaimei Wang Jiaxu Yan Xiaoqin Zou Guangshan Zhu Faculty of Chemistry Northeast Normal UniversityChangchun130024China Key Laboratory of UV-Emitting Materials and Technology of Ministry of Education Northeast Normal UniversityChangchun130024China

Ultrathin zeolite membranes are of paramount importance in accelerating gas transport during membrane separation,and lowering down their membrane thicknesses to submicron scale is deemed to be very ***,we develop an advanced approach of surface gel conversion for synthesis of submicron-thick pure silica MFI(silicalite-1)zeolite *** gel is prepared by finely adjusting the precursor composition,enabling its reduced *** unfavorable wetting of the support surface can effectively prevent gel penetration into alumina support *** by the seeds,the surface gel is directly and fully crystallized into an MFI zeolite membrane with minimal water steam.A membrane with a thickness of 500 nm is successfully acquired and it is free of visible ***,the as-synthesized membranes exhibit rapid and selective separation of hexane isomers by virtue of unprecedentedly high n-hexane permeance of 24.5×10^−7 mol m^−2 s^−1 Pa^−1 and impressive separation factors of 13.3-22.6 for n-hexane over its *** developed approach is of practical interest for sustainable synthesis of high-quality zeolite membranes.

关键词： zeolite synthesis silica gel chemistry thin membrane hexane separation isomer selectivity

Designing ABC-6 family small pore zeolites by epitaxial growth approach

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Chinese Chemical Letters 2024年第3期35卷 508-512页

作者： Xiaohui Cui Jia Lv Chao Ma Yujiao Wang Zhenghao Jia Daliang Zhang Peng Guo Zhongmin Liu Henan Institute of Advanced Technology Zhengzhou UniversityZhengzhou 450001China National Engineering Research Center of Lower-Carbon Catalysis Technology Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China Multi-scale Porous Materials Center Institute of Advanced Interdisciplinary Studies&School of Chemistry EngineeringChongqing UniversityChongqing 400044China University of Chinese Academy of Sciences Beijing 100049China Division of Energy Research Resources Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China

Aluminosilicate small pore zeolites belonging to ABC-6 family play crucially important roles in the high methanol conversion with the high selectivity of light olefins,gas separation and storage,and selective catalytic reduction of NO_(x).In this work,we report a general method,called the epitaxial growth approach,for designing ABC-6 family small pore *** is mainly realized through the epitaxial growth on the nonporous SOD-type zeolite in the presence of inorganic cations(Na^(+)and K^(+))combined with a variety of organic structure directing agents(OSDAs).In this case,a series of ABC-6 family small pore zeolites such as ERI-,SWY-,LEV-,AFX-,and PTT-type zeolites have been successfully synthesized within a few *** importantly,the advanced focused ion beam(FIB)and the low-dose high-resolution transmission electron microscopy(HRTEM)imaging technique have been utilized for unraveling the zeolite heterojunction at the atomic level during the epitaxial growth *** turns out(222)crystallographic planes of the SOD-type zeolite substrate provide unique pre-building units,which facilitate the growth of targeted ABC-6 family small pore zeolites along its ***,the morphologies of ERI-type zeolite can also be tuned through the epitaxial growth approach,achieving a longer lifetime in the methanol conversion.

关键词： zeolite structure zeolite synthesis Structural characterizations Low-dose imaging Focused ion beam

Templates for the synthesis of zeolites

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Chinese Journal of Structural Chemistry 2024年第4期43卷 48-58页

作者： Huimin Luan Qinming Wu Jianping Wu Xiangju Meng Feng-Shou Xiao College of Chemical and Biological Engineering Zhejiang UniversityHangzhou310027China Kente Catalysts Inc. Fengxi West RoadModern Industrial ClusterXianju CountyZhejiang317300China Key Laboratory of Applied Chemistry of Zhejiang Province Department of ChemistryZhejiang UniversityHangzhou310007China

Though zeolites have been successfully synthesized for several decades,the roles of templates for zeolite synthesis are still not fully understood ***,many types of templates have been employed such as inorganic alkali metal ions,organic quaternary ammonium cations,organic amines,organic quaternary phosphonium cations,metal complexes and zeolite seeds,and the roles are mainly summarized into three aspects:structure-directing,space-filling and *** order to synthesize zeolites efficiently,the proposed principles to guide zeolite synthesis are the stabilization of energy between templates and zeolite framework,charge density mis-matching(CDM)and structure matching between zeolite frameworks and *** purpose of this review is to briefly summarize the progresses in recent years,clearly showing the roles of the templates for zeolite synthesis.

关键词： zeolites Templates zeolite synthesis zeolite structure