CHINESE JOURNAL OF CHEMISTRY
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2017
·Vol. 35
·期 5
·572-576
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IF 1.852
Qinming Wu,Xiaolong Liu,Longfeng Zhu,Xiangju Meng,Feng Deng,Fengtao Fan,Zhaochi Feng,Can Li,Stefan Maurer,Mathias Feyen,Ulrich Müller,Feng-Shou Xiao
Development of the sustainable routes for synthesis of ITQ-family zeolites is very important because of their unique structures and excellent catalytic and adsorptive properties. The burden of costly raw materials and low efficiency of synthesis put a strong challenge for their widespread commercial application. Here, we show an alternative and simple route for synthesis of ITQ-12, ITQ-13, and ITQ-17 zeolites using commercially available organic templates by a facile grinding process of anhydrous starting raw solids, followed by heating at 140—180 °C. Compared with the conventional hydrothermal synthesis, this approach has obvious advantages such as employment of low-cost organic templates with very high effectiveness, high yield of zeolite products, short crystallization time, and relatively simple procedures. This methodology might open a pathway to synthesize ITQ zeolites with more sustainable manner.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
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2019
·
IF 4.182
Yeqing Wang,Jian Zhang,Xiangju Meng,Shichao Han,Qiuyan Zhu,Na Sheng,Liang Wang,Feng-Shou Xiao
In this work, we show sustainable and efficient synthesis of nanosized EMT zeolite under organotemplate-free and solvent-free conditions, which not only completely avoids the use of organic templates for production of NOx and CO 2 but also effectively reduces the formation of polluted water. In addition, the yield of EMT zeolite is significantly enhanced by this route, compared with conventional hydrothermal synthesis . The nanosized EMT zeolite obtained has good crystallinity, uniform crystal size distribution, and high surface area. Ion-exchange tests show that the nanosized EMT zeolite owes high Ca 2+ and Mg 2+ ion exchange capacity at room temperature, which is potentially important for softening hard water in the industrial processes. Catalytic tests in Knoevenagel condensation show that the nanosized EMT zeolite exhibits higher activity than that of the EMT zeolite synthesized using organic template, indicating the importance of the nanosized EMT zeolite as a base catalyst.
研究领域:
材料科学
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环境科学
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催化化学
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DOI
高影响因子
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
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2016
·Vol. 2016
·期 9
·1364-1368
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IF 2.686
Yeqing Wang,Chenqi Zhu,Jing Qiu,Fan Jiang,Xiangju Meng,Xiong Wang,Chi Lei,Yinying Jin,Shuxiang Pan,Feng-Shou Xiao
Graphical A high-silica aluminosilicate zeolite with a TON structure designated as ZJM-4 was successfully synthesized in the absence of any organic templates and zeolite seeds. This route has efficient silica utilization, and the zeolite product has a stable tetrahedral aluminum species. A high-silica zeolite with a TON structure designated as ZJM-4 was successfully synthesized in the absence of any organic templates and zeolite seeds. Many factors such as the SiO 2 /K 2 O ratio, Si/Al ratio, SiO 2 /H 2 O in the starting aluminosilicate gels, crystallization temperature, and crystallization time strongly influence the formation of the ZJM-4 zeolite. Interestingly, this synthesis shows very efficient silica utilization in the starting gels (>80 %). Catalytic tests on the isomerization of m -xylene to p -xylene show that the ZJM-4 catalyst has high selectivity to p -xylene (ca. 80 %), which could be potentially important for industrial applications for the ZJM-4 zeolite as a candidate catalyst in the future.
研究领域:
材料化学
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催化科学
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产品关联
DOI
高影响因子
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
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2022
·Vol. 2022
·期 16
·e202200130
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IF 2.551
Shengqiang Zhou,Lipeng Zhou,Yunlai Su,Xiaomei Yang,Hao He
Graphical Sn-Beta was synthesized by a quasi-solid-phase method without adding additional solvent. Low amount of template and mineralizer was used as compared with traditional route. Sn-Beta zeolites were successfully synthesized through a quasi-solid-phase method by grinding the raw materials and then crystallizing in solid state. The method employed small amount of tetraethyl ammonium hydroxide (TEAOH) and no additional solvent, except for the water contained in template solution. The synthesis conditions including amount of TEAOH and water, and crystallization time were explored. Under optimized conditions, the obtained sample showed high crystallinity and capped square bipyramidal crystals. The diffuse reflectance ultraviolet-visible spectra and Fourier transform infrared spectra of CD 3 CN and pyridine adsorption were used to characterize the state of Sn and acidity in Sn-Beta sample. Sn 4+ ions were introduced into the framework which generated strong Lewis acid sites. The sample synthesized by quasi-solid-phase method gave 38.5 % methyl lactate (MLA) yield for the conversion of glucose to MLA, which is comparable to that of Sn-Beta prepared with conventional hydrothermal method (39.4 %).
研究领域:
材料科学
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催化化学
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
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2021
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IF 5.455
Deyu Si,Meihua Zhu,Ronghui You,Yuqin Li,Ting Wu,Tian Gui,Na Hu,Izumi Kumakiri,Xiangshu Chen,Hidetoshi Kita
Aluminum-rich ZSM-5 zeolite membranes are prepared on α-alumina support through organic template free precursor gels by secondary hydrothermal synthesis , microstructure of the membrane through the different Si/Al ratio and alkali metal fluoride synthesis gel are discussed in this work. Alkali metal fluorides have a significant influence on the synthesis of aluminum-rich ZSM-5 zeolite membranes without organic template, which are realized by the synergistic reaction of the “bridging” and “salting-out” effects. Sodium fluoride and potassium fluoride could produce dense and needle-like zeolites layer on the supports by an extremely low Si/Al ratio synthesis gel (Si/Al <10). When the Si/Al ratio of the initial synthesis gel is 18.52, the compact and prismatic ZSM-5 zeolites are fully covered on the supports with sodium fluoride, potassium fluoride or lithium fluoride. There are few of ZSM-5 zeolites could form on the support by cesium fluoride containing synthesis gel.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
Journal of Materials Chemistry A
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2018
·Vol. 6
·期 18
·8705-8711
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IF 9.931
Hao Xu,Qinming Wu,Yueying Chu,Jingang Jiang,Ling Zhang,Shuxiang Pan,Changsheng Zhang,Longfeng Zhu,Feng Deng,Xiangju Meng,Stefan Maurer,Robert McGuire,Andrei-Nicolae Parvulescu,Ulrich Müller,Feng-Shou Xiao
2,6-methyl-N-methylpyridinium, as a novel organic template, is employed for the synthesis of RTH aluminosilicate zeolite with a SiO2/Al2O3 ratio of 17.6. The amount of 2,6-methyl-N-methylpyridinium template, the Na2O/SiO2 ratio, the SiO2/Al2O3 ratio, and the H2O/SiO2 ratio in the starting gel significantly influence the crystallization of RTH zeolite. Several analytical methods such as XRD, SEM, N2 sorption, TG-DTA, DRIFT and NMR were employed for the characterisation of the obtained RTH zeolites and to understand the crystallization process with the new template. Very interestingly, the crystallization of RTH zeolite with the new template takes a very short time (12 h at 130 °C and 50 min at 240 °C) compared with conventional RTH zeolite synthesis reported in the literature (72 h at 130 °C). Theoretical calculations show that this novel organic template has lower interaction energies for zeolite cage space filling than those of the organic templates previously reported in the literature, which lead to stronger structural directing. Kinetic results show that the activation energy of this novel organic template is much lower than that of the traditional one. Catalytic tests show that copper exchanged RTH zeolite (Cu-RTH) exhibits good catalytic properties in the NH3-SCR reaction and the H-RTH zeolite catalyst has excellent selectivities for ethylene and propylene in MTO reactions.
研究领域:
催化材料
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化学工程
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环境科学
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DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2020
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IF 16.683
Juan Zhang,Yulong Shan,Ling Zhang,Jinpeng Du,Hong He,Shichao Han,Chi Lei,Sen Wang,Weibin Fan,Zhaochi Feng,Xiaolong Liu,Xiangju Meng,Feng-Shou Xiao
As a commerical catalyst of high silica CHA zeolite for NH 3 -SCR reaction, controllable Al sites in CHA framework for improving catalytic performance are rarely reported. In this work, two organic templates (TMAda + and DMCHA + ) were employed to prepare aluminosilicate CHA zeolite with similar Si/Al ratios, donated as CHA-T and CHA-D. Detailed characterizations demonstrate that two completely distinguishable crystallization pathways can be identified as the preferential formation of smaller D6R units for CHA-D with DMCHA + and larger 8MRs for CHA-T with TMAda + , resulting in spatially closer Al sites in CHA-D than CHA-T. As an interpretation, CHA-D with more paired Al atoms in 6MR generating more hydrothermally stable Cu 2+ -2Z sites contributes to higher activity than CHA-T at 400−550 °C. These results suggest that the crystallization pathways directed by rational choice of organic templates might be responsible for the controllable Al sites in the framework, which is important for designing efficient NH 3 -SCR catalysts.
研究领域:
材料科学
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催化化学
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DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
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2025
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IF 3.2
Zhu Mengxuan,Liu Yifan,Ma Jiaxin,Wang Longyang,Wang Rui,Jiang Heng,Jin Changzi
Developing the novel green routes for synthesis of important aluminosilicate zeolites is of significant for theoretical research and practical application. In this work, MCM-22 zeolite with MWW-topology was synthesized through seed-assisted interzeolite transformation from FAU zeolite without using additional organic template. The key influence factor to the synthesis process was investigated and the zeolite products were characterized by a series of modern techniques. It has been shown that not only the presence of MCM-22 seed, but also the appropriate SiO 2 /Al 2 O 3 and Na 2 O/SiO 2 molar ratio of starting synthesis gel with were crucial to synthesize pure MWW zeolite. The hexamethyleneimine template occluded in seed also played a key role in successful interzeolite transformation, but did not participate structure-directing of MWW product. Although the zeolite synthesized by interzeolite transformation showed lower surface area and pore volume compared with MCM-22 zeolite prepared by conventional route, the Pt modified sample exhibited promising catalytic performance in hydroisomerization of n -heptane. Graphical
研究领域:
材料科学
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催化化学
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产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
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2019
·
IF 2.291
Xiangping Li,Han Yin,Jianguang Zhang,Juping Liu,Guanyi Chen
Template removing approaches can significantly impact the physiochemical properties of mesoporous molecular sieve materials. In order to better understand the relationship between template removing approaches and the properties of Ni/Al-SBA-15, four kinds of template removing approaches were introduced to remove the organic template from Al-SBA-15, respectively. The structural characteristics of these materials were analyzed by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray fluorescence (XRF), powder X-ray diffraction (XRD), N 2 -sorption, Fourier transform infrared spectra (FT-IR), infrared spectra of pyridine adsorption (Py-FTIR), magic angle spinning-nuclear magnetic resonance (MAS-NMR), X-ray photoelectron spectroscopy (XPS) and gas chromatography-mass spectrometry (GC-MS). Ni/Al-SBA-15 of which the organic template was removed by two-step calcination method had the maximum specific surface area (619 m 2 /g). In contrast, Ni/Al-SBA-15 of which the organic template was removed using solvent extraction approaches had the lowest specific surface area (555 m 2 /g). The mesopore diameter of Ni/Al-SBA-15, using electric heating digestion method to remove the template, was significantly increased and the wall thickness was significantly decreased to 11.62 nm in comparison with the other samples. The selectivity of products during the process of eugenol hydrodeoxygenation was investigated. High hydrocarbons were obtained during catalytic hydrodeoxygenation over Ni/Al-SBA-15 of which the organic template was removed by using solvent extraction approaches. Compared with direct calcination process, two-step calcination was more effective in removing template and the corresponding catalyst was much more suitable for the hydrodeoxygenation process.
研究领域:
材料科学
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催化化学
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Feng Ye,Shuanshi Fan,Xuemei Lang,Yanhong Wang,Gang Li
Silicalite-1 zeolite membranes were successfully activated at 300–350 °C in a hydrogen atmosphere. FTIR, TGA, and N 2 adsorption-desorption characterizations confirmed that the amount of the organic structure directing agent (OSDA) residue in silicalite-1 zeolite channels was tunable. The H 2 -calcined membrane showed a lower gas permeance than that of the air-calcined membrane due to the partial pore blockage by the OSDA residue. The permeance of H 2 and CO 2 increased with increasing temperature, showing an activated diffusion-like mechanism. The activation energies for the permeation of H 2 and CO 2 were in the range of 1.63–4.15 and 0.76–5.90 kJ mol −1 , respectively, which confirmed the reduced average membrane pore size and different pore surface chemistry due to the presence of the OSDA residue in the membrane. Significant interactions between CO 2 molecules and OSDA residues confined in the membrane resulted in a notably lower CO 2 permeance compared to N 2 and CH 4 , despite CO 2 having a smaller kinetic diameter. Enhanced H 2 /CO 2 selectivity in the silicalite-1 zeolite membrane, featuring confined OSDA residue, was attributed to the reduction in membrane pore size and the fine-tuning of pore surface chemistry.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
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2022
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IF 8.047
Yuan Liang,Shaoxiang Xu,Meihua Zhu,Jiamin Jiang,Jiao Zhang,Goubing Zhou,Na Hu,Xiangshu Chen,Hidetoshi Kita
In the absence of boric acid, the tubular Ti-MWW zeolite membranes are prepared with dual organic template agents and potassium carbonate by secondary hydrothermal synthesis. 12MR cage and 10 MR of the MWW zeolite topology structure is stabilized by TMAdaOH and HMI organic template agents, K + cations is a critical mineralization agent for preparing Ti-MWW zeolite membrane with bi-layer Ti-MWW zeolites layer in this work. Besides, ion-exchange could greatly improve the catalytic performance of the Ti-MWW zeolite membrane for phenol hydroxylation with H 2 O 2 , influences of ammonium salt, ion-exchange time and temperature on the micro-structure and catalytic performance are investigated. The upper network-like Ti-MWW zeolite layer could be dissolved and removed by ion-exchange with 0.5 M (NH 4 ) 2 SO 4 solution at 60 °C for 24 h, and the “lying” Ti-MWW zeolites layer is kept on the mullite support. On the other hand, ion-exchange could promote the transformation of hexacoordinated extra-framework titanium species to tetracoordinated state in the framework, part of K + cations of Ti-MWW zeolites are replaced with NH 4 + cations. Total flux and phenol conversion of the ion-exchanged Ti-MWW zeolite membrane are 14.89 kg·m −2 ·h −1 and 36.49 % for phenol hydroxylation by H 2 O 2 at 50 °C.
研究领域:
材料科学
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催化化学
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DOI
高影响因子
CATALYSIS TODAY
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2022
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IF 6.562
Huimin Luan,Wei Chen,Qinming Wu,Anmin Zheng,Xiangju Meng,Trees De Baerdemaeker,Andrei-Nicolae Parvulescu,Ulrich Müller,Feng-Shou Xiao
Despite very successful synthesis of many pure silica or germanosilicate zeolites, there are still challenges for direct synthesis of their aluminosilicate forms. As a typical example, it is easy to synthesize germanosilicate ITH, but difficult for direct synthesis of its aluminosilicate form. Recently, cationic oligomer has been successfully templated for direct formation of aluminosilicate ITH, but relatively complex steps for controlling molecular weight of the cationic oligomer strongly hinder the practical production of zeolite products. Herein, it is shown an alternative route for direct synthesis of aluminosilicate ITH zeolite in the presence of a small organic template with both structural directing ability for the ITH structure and strong interaction ability to aluminum species. Characterizations of the zeolite products with Si/Al ratios from 46 to 148 show high crystallinity, nanosheet-like crystal morphology, large microporous surface area (338 m 2 /g), high micropore volume (0.16 cm 3 /g), four-coordinated Al species, controllable acidic sites, and extraordinary hydrothermal stability (hydrothermal aging at 800 °C for 5 h with 10% water steaming). Catalytic tests in methanol-to-propylene (MTP) show that the aluminosilicate ITH zeolite has higher selectivity for propylene than that of commercial ZSM-5 zeolite with similar Si/Al ratio, which provides a candidate catalyst for MTP reaction in the near future.
研究领域:
化学
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材料科学
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催化
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产品关联
DOI
高影响因子
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