SEPARATION AND PURIFICATION TECHNOLOGY
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2025
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IF 9
Qing Xu,Jianyi Lu,Zhiyong Zhou,Yujia Jin
Synthesis of zeolite from industrial wastes has become an important environmental protection strategy. This study explored the synthesis of nano-sized NaX and NaY zeolites from coal/rice husk co-combustion ash (co-ash) using alkali-melting-hydrothermal synthesis and seed guiding methods, followed by modification with Li + and K + exchange. NaY zeolite, synthesized at a SiO 2 /Al 2 O 3 ratio of 5 and crystallization temperature of 100 °C, exhibited the most complete crystal structure and optimal CO 2 adsorption capacity. The specific surface area (SSA) of NaX and NaY zeolites (583.0 m 2 /g and 790.1 m 2 /g, respectively) are comparable to those of commercial zeolites, emphasizing their structural parity, and demonstrating their potential as effective CO 2 adsorbents. NaY demonstrated a CO 2 adsorption capacity of 5.31 mmol/g at 298.15 K and 1 bar, competitive with other conventionally synthesized and commercial zeolites. Cation exchange had a minimal impact on CO 2 adsorption of NaY, with LiX improving capacity by 11.65 % compared to NaX, while LiY showed only a 2.94 % increase. K + exchange negatively affected both zeolites. Kinetic and thermodynamic analyses, using the proposed first-order (PFO) and Langmuir-Freundlich models, indicated that CO 2 adsorption is a rapid physisorption process with thermal effects ranging from 22 to 41 kJ/mol. Both zeolites exhibited excellent CO 2 /N 2 selectivity and regeneration stability, with the loss of adsorption capacity retaining only 10.57 % and 9.63 % for NaX and NaY after fifteen cycles. This highlights their potential as efficient CO 2 adsorbents.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
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2019
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IF 4.182
Junjie Zhou,Chen Zhou,Kai Xu,Jürgen Caro,Aisheng Huang
Thin, phase-pure and well inter-grown zeolite FAU membranes are synthesized upon modifying the tubular supports using 3-aminopropyltriethoxysilane (APTES). The as-synthesized zeolite FAU membranes are evaluated in the dewatering of dimethyl carbonate (DMC) by pervaporation . Due to the large pore size (0.74 nm) and high hydrophilicity of zeolite FAU, the prepared zeolite FAU membranes exhibit high water flux and separation performance for the separation of H 2 O and DMC. With increasing the temperature or water content in the feed, the zeolite FAU membranes show higher flux while maintaining high separation factors. Further, for dewatering of 10 wt% H 2 O/90 wt% DMC mixtures at 353 K in a lab device, the DMC concentration in the feed side reaches 99% after continuously dewatering over 9 h. Besides, the zeolite FAU membranes are also successfully prepared on commercial tubular size of 80 cm and 100 cm long α-Al 2 O 3 tubes. The obtained membranes show high separation performance for the dewatering of DMC solution as well. The high-performance zeolite FAU membrane offers great potential for dewatering of DMC solutions in industry.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2024
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IF 8.4
Qing Wang,Yu Guo,Nong Xu,Qiao Liu,Bin Wang,Long Fan,Lingyun Zhang,Rongfei Zhou
Membrane-based pervaporation (PV) is an energy-efficient separation technology for liquid molecular mixtures, which is an increasingly important function in chemical industries. This work accomplished the first synthesis of high-performance FAU (NaX type) zeolite membranes on α-alumina tubular supports via the secondary growth method using 50 nm nanoseeds. The effects that the synthesis parameters exerted on the crystal structures, morphologies, and PV performance of FAU membranes were systematically investigated. The nanosized seeds showed high levels of activity that promoted the rapid growth of the zeolite layer. In addition, either extending the crystallization time or raising the temperature readily caused trans -crystallization to form NaP impurity zeolites, which decreased the membrane flux and separation factor. When synthesis conditions were optimized, a high-quality and pure-phase FAU membrane was obtained and tested for the permeation of single gases and for the PV dehydration of various organic solvents (methanol, ethanol, n-propanol, iso-propanol, and tert-butanol). The relationships between the single-gas permeance, PV permeance, and polarity index were investigated using a similar size range of permeate molecules (0.289–0.5061 nm). The results show that gas permeance exhibits Knudsen selectivity. The PV permeance, however, correlated well with the polarity index of the permeate, which indicates that PV dehydration through the FAU membrane is controlled by an adsorption-diffusion mechanism. Moreover, the correlation provides a new tool for predicting PV performance. Compared with studies using FAU membranes, the as-synthesized FAU membrane features good reproducibility, excellent stability, and high PV performance, which suggests the great potential of FAU membranes for use in industrial organic solvent dehydration.
研究领域:
化学工程
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材料科学
✓ 已验证
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
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
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2022
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IF 6.137
Chuanxi Tan,Chenji He,Yueyue Sun,Hui Dong,Man Ge,Xianping Xia
The active carbon supported palladium catalyst (Pd/C) is commonly used for hydrogenation of 1,4-bis(phenylethynyl) benzene (DEB), to avoid its disadvantage of easy combustion, a nonflammable Pd-containing zeolite was developed as a novel catalyst for the DEB hydrogenation. In the present work, this Pd-containing zeolite catalyst was synthesized via a one-pot hydrothermal technique, and its structure and catalytic performance were investigated. The results show that the support of this prepared Pd-containing zeolite catalyst is a layer-like FAU zeolite with a hierarchical pore structure, and the Pd particles is embedded uniformly inside the layer-like FAU zeolite with an average size of 2.02 ± 0.41 nm. The results also show that the catalytic performance of this prepared Pd-containing zeolite catalyst (Pd@FAU) is much better than that of the traditional Pd/C catalyst with the same content of Pd particles, the DEB-Pd@FAU mixture can reach its maximal hydrogen uptake capacity of 257.41 ml/g in 20 h, and the DEB-Pd/C mixture can only reach its maximum of 223.81 ml/g in 45 h. These differences are mainly caused by that the Pd particles in the prepared Pd@FAU catalyst has a smaller size, a better dispersion and a more metallic Pd species than those in the Pd/C catalyst. All these results indicate that the Pd@FAU catalyst would be a promising substitute for the traditional Pd/C catalyst for hydrogenation of DEB.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
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2019
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IF 4.182
Xu Zhang,Yaquan Wang,Xiao Wang,Hengbao Chen,Hongyao Li,Chao Sun,Liying Sun,Chunyang Fan,Cui Wang
In this study, an efficient route was developed to prepare high quality erionite (ERI) zeolite by hydrothermal conversion of faujasite (FAU) zeolite as an aluminosilicate source in the presence of N,N -dimethylpiperidinium hydroxide (DMPOH). Pure ERI zeolite was successfully synthesized within only 8 h by carefully controlling the alkalinity (OH − /SiO 2 ) of the initial gel and the proportion of DMP + and K + . Compared with the conventional ERI zeolite synthesized via a Charge Density Mismatch method, the FAU-derived ERI zeolites show superior properties such as higher crystallinity , smaller crystal size, larger micropore volume and better hydrothermal stability. In addition, catalytic test in the ethanol dehydration reaction shows that the ERI zeolites obtained from FAU exhibit extraordinary performances to those of the conventional one. Finally, crystallization process from FAU to ERI was investigated in detail by UV Raman and XRD . The results show that the framework of ERI zeolite is formed by rearrangement of 4-rings generated from the initial FAU zeolite.
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
危险品化学品经营许可证（带存储）