DESALINATION
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2024
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IF 8.3
Wen Guo,Zixin Lin,Kun Jiang,Hao Li,Xiangfeng Liang,Weizhong An,Huizhou Liu,Haiyan Luo,Haoyu Yao
The extraction of uranium from seawater is not only crucial from a strategic standpoint but also poses significant technical challenges. In this work, a series of novel bifunctionalized mesoporous silicas were prepared through a straightforward method, utilizing the structural characteristics of SBA-15 and synergistic effect of functional groups. The impact of pH value, initial uranium concentration, temperature, and duration on uranium adsorption was investigated through a series of batch experiments. The bifunctional modified SBA-15 demonstrated rapid uranium adsorption, which was a spontaneous endothermic reaction and conformed to the pseudo-second-order model. Thereinto, SBA-15 modified with aldoxime and amino group (SBA-15-SAO-N) exhibited the best uranium adsorption performance, with a maximum adsorption capacity of 701.85 mg·g −1 at 298 K and pH 6, an increase of 146 % compared to SBA-15-SAO. SBA-15-SAO-N exhibits excellent U/V selectivity (selectivity coefficient of 30) in the coexistence of U and V solutions, and it still maintains high adsorption capacity after five adsorption-desorption cycles. In actual seawater conditions, the adsorption capacity of SBA-15-SAO-N was 135.26 μg·g −1 . By combining DFT calculations and characterization, the coordination model and interaction energy between functional groups and uranyl were elucidated, revealing that introducing bifunctional groups can enhance the binding strength of adsorbents to uranium and form more stable complexes, thereby improving adsorption capacity and selectivity. These results indicate that bifunctional modified mesoporous silica offers a promising strategy for recovering uranium resources from seawater.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
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2024
·
IF 5.9
Ruixiang Zhou,Weilong Li,Jiayi Li,Jiwen Hu,Xuefeng Gui,Yonglu Dong,Hongcai Yang,Xiaohua Huang,Shudong Lin
Polyurethane materials are widely used, yet their thermal hazards remain underexplored. This study investigates the solvent-free polyaddition of hexamethylene diisocyanate (HDI) and hydroxyethyl acrylate (HEA) under trace moisture conditions. Titration results showed that moisture significantly reduces the reaction rate, while Karl Fischer titration confirmed effective moisture removal using molecular sieves. NMR and FTIR revealed that dehydration enhances isocyanate electrophilicity and hydroxyl nucleophilicity, accelerating the reaction. DSC indicated that moisture induces additional exothermic peaks due to side reactions, and ARC testing showed elevated initial temperatures and reduced adiabatic temperature rise. A kinetic model revealed a consistent reaction order of 0.8, regardless of moisture. T D8 and T D24 were predicted, and a risk matrix assessed the thermal hazards. This study provides essential guidance for the safe and efficient development of novel eco-friendly polyurethane formulations and offers valuable insights for large-scale industrial safety.
研究领域:
材料科学
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化学工程
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安全工程
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产品关联
DOI
高影响因子
Greenhouse Gases-Science and Technology
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2024
·Vol. 14
·期 6
·954-976
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IF 2.7
Xianglian Wu,Aisha Nulahong,Conghui Miao,Qinghua Liu,Jiangyuan Li,Changmin Tuo
In this work, an alkali melting-pickling assisted solid phase synthesis method of S-1 zeolite molecular sieve with excellent adsorption properties for CO 2 was successfully developed by using solid waste fly ash. SiO 2 with a purity of up to 97.84% was successfully extracted by using alkaline fusion activation, high temperature calcination and pickling. The CO 2 adsorption capacity of the prepared SiO 2 was 0.51 mmol/g at 298 K and 1 bar. Silicalite-1 molecular sieve was prepared by solid phase synthesis method using SiO 2 extracted from fly ash as silicon source. The results showed that the prepared Silicalite-1 had good morphology and relatively high crystallinity. The specific surface area is 623.30 m 2 /g, and the total pore volume is 0.31 cm 3 /g. In addition, the adsorption capacity of CO 2 was 2.05 mmol/g at 298 K and 1 bar. Compared with the prepared SiO 2 , the adsorption capacity of CO 2 by Silicalite-1 molecular sieve increased by four times. Moreover, under the test condition of 298 K, it has a high selectivity coefficient for CO 2 /N 2 mixed gas, and after 10 times of adsorption-desorption cycle tests, the adsorption capacity of Silicalite-1 molecular sieve for CO 2 does not change significantly, and its adsorption rate can still be as high as 89.31%. The results indicate that Silicalite-1 molecular sieve prepared by solid phase synthesis method has good adsorption selectivity and adsorption–desorption cycle regeneration stability, and can be used in the field of CO 2 adsorption, separation and purification. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
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2024
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IF 2.8
Xu Gao,Aihu Feng,Le Mi,Yang Yu,Yun Yu
Adsorption is one of the most effective methods for controlling the concentration of VOCs pollution. In this work, the hierarchical NaY zeolites with size-controlled mesopores in the range of 2–5 nm are obtained via NH 4 HF 2 -etching and surfactant-templating process. By using the different cationic surfactant (C n TAB), we fabricate the surfactant-templated zeolite with controllable mesopores, and improve its adsorption capacity for toluene. In addition, the modified zeolite’s hydrophobicity is enhanced, and it maintains a high adsorption capacity in a complex humid environment.
研究领域:
材料科学
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环境工程
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2020
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IF 3.573
Hang Li,Yi Zhai,Xubin Zhang,Guojun Lv,Yu Shen,Xuqing Wang,Tao Jiang,Yuzhou Wu
Hierarchical iron-containing TS-1 zeolites (FTS) were successfully synthesized via post-treatment desilication over microporous Fe-TS-1, which were prepared through a one-step hydrothermal synthesis. The prepared samples were characterized by X-ray diffraction, N2 adsorption–desorption, field-emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, ultraviolet visible spectroscopy, and X-ray fluorescence spectrometry. The experimental results illustrated that the MFI structure of all the FTS samples remained unchanged after NaOH desilication and acid treatment. The newly created mesopores can be controlled by changing the amount of framework Fe, as the extraction of Si could be affected because of the inhibitory effect of iron species during the desilication process. The catalytic performance of the prepared samples in phenol hydroxylation with H2O2 was investigated. Among all the samples, FTS-50-D showed a highest phenol conversion of 45.2% and a dihydroxybenzene selectivity of 95.2%. Besides, FTS-50-D also showed good reusability for five recycling tests.
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
MICROPOROUS AND MESOPOROUS MATERIALS
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2019
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IF 4.182
Aihu Feng,Yang Yu,Le Mi,Yunzhen Cao,Yun Yu,Lixin Song
The non-framework aluminum is inevitably formed in the process of preparing the ultra-stable Y zeolite (USY), which severely blocks the mesopores of USY zeolite. It is necessary to treat the USY with the appropriate acid and/or alkali. In this paper, the USY zeolite is firstly dealuminated with NH 4 HF 2 solution and then desiliconized with NaOH or NH 4 OH solution. The effect and mechanism of NH 4 HF 2 and different alkali treatments on the structural and textural property of USY zeolite are elaborately demonstrated. It is found that the non-framework Al remaining in the mesopores of USY is significantly removed by the NH 4 HF 2 solution. The desiliconization reaction is more likely to start near the mesoporous wall because the Al concentration in here is low and the repulsive force against OH − is weak. The OH − ions from NaOH solution not only etch the framework Si near the inner wall of the mesopores, but also remove the Si on the surface of NH 4 HF 2 -etched USY zeolite. However, the concentration of OH − ions is too low when NH 4 OH is used as the desiliconization agent, the OH − ions just react with silicon around the mesopores. Therefore, the NaOH/NH 4 HF 2 -etched USY contains both some micropores and macropores, and the NH 4 OH/NH 4 HF 2 -etched USY only possesses more mesopores with pore sizes of ～10 nm. In addition, NaOH/NH 4 HF 2 -etched USY exhibits excellent toluene adsorption performance at low pressure stage, while NH 4 OH/NH 4 HF 2 -etched USY has the highest adsorption capacity on toluene at high pressure stage.
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
DALTON TRANSACTIONS
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2014
·Vol. 43
·期 37
·14123-14131
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IF 4.097
Lei Chen,Bing Yan
Both zeolite A/L and SBA-15 have been used to assemble novel photofunctional multi-component lanthanide hybrid materials. Microporous zeolites A/L are first functionalized by embedding lanthanide or zinc complexes (TTA = thenoyltrifluoroacetone, TAA = trifluoroacetone, bipy = 2,2′-bipyridyl) into the pores of zeolite A/L, and then the surface of functionalized zeolite A/L is modified via covalent linkers from aromatic carboxylic acids (para-aminobenzoic acid ABA and para-hydroxyl benzoic acid HBA) grafted by 3-(triethoxysilyl)-propyl isocyanate (TEPIC). On the other hand, SBA-15 is modified by grafting covalent linker phen-Si from the modification of 1,10-phenanthroline (phen) with TEPIC. Further, another lanthanide ion is used to link both functionalized zeolites, A/L and SBA-15, through the coordination with the two covalent linkers, ABS-Si (HBA-Si) and phen-Si, respectively. Subsequently, the obtained multicomponent microporous–mesoporous hybrid materials are assembled and characterized using XRD, FT-IR, UV-vis DRS, SEM, TEM and luminescent approaches (spectra, lifetimes and quantum efficiencies). These hybrids with both microporous zeolite and SBA-15 mesoporous host possess favourable luminescent performance and some hybrid systems present the high quantum efficiencies of 90%. Besides, the luminescent color can be tuned by adjusting the composition of these hybrids, among which four hybrids (S-phen-Eu-HBA-[ZA-Tb-bipy], S-phen-Eu-HBA-[ZA-Zn-bipy], S-phen-Eu-ABA-[ZA-Tb-TAA], S-phen-Eu-ABA-[ZL-Tb-bipy]) can be integrated to white light emission.
研究领域:
材料科学
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光化学
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纳米技术
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产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2022
·
IF 9.136
Yonghou Xiao,Jiahui Fu,Heyang Zhu,Qidong Zhao,Liang Zhou
The diffusion limitation owing to the long and narrow pore structure in traditional ZSM-5 zeolite could restrain the adsorptive desulfurization performance towards thiophene sulfur compounds from fuels. Herein, ZSM-5 zeolite nanocrystals were successfully fabricated using steam-assisted gel crystallization strategy to control the size of zeolite particles within 70 ∼ 160 nm. Compared to traditional micron ZSM-5, ZSM-5 zeolite nanocrystals could effectively reduce the diffusion pathway, enlarge the specific surface area, and increase exposure of adsorption sites, which could enhance the desulfurization performance. ZSM-5 nanocrystals with a mole ratio SiO 2 /Al 2 O 3 of 200 exhibited a satisfactory desulfurization efficiency, and the breakthrough capacity attained 0.0509 mmol S/g adsorbent. After ZSM-5 nanocrystals were ion-exchanged with NH 4 + and Ag + , both mesoporous characteristics and the Lewis acid (L-acid) sites were enhanced, which promoted the adsorption desulfurization performance. Furthermore, nanocrystalline ZSM-5 and Ag/ZSM-5 also exhibited acceptable regeneration performance. This study is expected to provide an effective strategy and a facile method to prepare nanocrystalline ZSM-5 based adsorbents for the development of efficient desulfurization materials.
研究领域:
化学工程
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材料科学
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产品关联
DOI
高影响因子
Crystals
·
2021
·Vol. 11
·期 10
·1247
·
IF 2.589
Changsheng Zhang,Kai Fan,Ge Ma,Chi Lei,Wei Xu,Jie Jiang,Bing Sun,Hongxing Zhang,Yunfeng Zhu,Song Wen
Hierarchical zeolites attract people’s attention due to their enhanced mass transfer properties in catalytic reactions. The research over obtaining these zeolites in green and efficient methods is of great significance for the current post-treatments and templating strategies tend to be costly for hierarchical zeolite synthesis. In this research, nanosized mesoporous ZSM-5 (SN-ZSM-5) zeolites have been synthesized without the addition of mesoscale templates under highly concentrated conditions. The physicochemical characteristics were systematically investigated by XRD, SEM, N2 sorption, TEM, and NMR. The SEM images showed ZSM-5 crystals with sizes between 50–110 nm were obtained. N2sorption and high-resolution TEM images gave direct evidence for the hierarchical structure of SN-ZSM-5. The forming mechanism for the hierarchical structure was proposed that the etching effect of the highly alkaline environment for the starting gels played a critical role in the formation of hierarchical structure. Catalytic tests in methanol-to-olefins (MTO) showed the SN-ZSM-5 performed a longer catalyst lifetime and higher propylene selectivity than the conventional ZSM-5 zeolites (C-ZSM-5) obtained from a traditional hydrothermal method. The features of hierarchical structure in the SN-ZSM-5 crystals and the sustainability for synthesis method could show a promising choice for wide applications of these SN-ZSM-5 zeolites in the future.Keywords:ZSM-5 zeolite;efficient synthesis;hierarchical;nano crystals
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
BIOMASS & BIOENERGY
·
2023
·
IF 6
Lihe Zhu,Xueting Shao,Xuejun Pan,Zhong Sun,Xiangyu Li,Xixin Duan,Junyou Shi
Catalytic conversion of waste biomass to furfural (FF) is an important valorization of lignocellulose . Heteropolyacid catalysts were designed for efficient aqueous-phase dehydration of saccharides by supporting phosphotungstic acid (H 3 PW 12 O 40 , abbreviated as PW 12 ) on H-ZSM-5 zeolite at different loadings (xPW 12 /ZSM-5, x = 10%, 20%, 30%, 40%, 50%). The PW 12 /ZSM-5 was used in the one-pot conversion of biomass (xylose, xylan , and corn stover) to FF in LiBr aqueous solution. The low PW 12 loading catalyst (10%PW 12 /ZSM-5) could efficiently convert biomass to FF with the yields of 73.3% (xylose) and 75.1% (xylan) at moderate temperature (130 °C), respectively. The PW 12 loading and acid sites distribution were crucial to the catalytic performance. Moreover, LiBr enhanced the yield of FF because of its Lewis acidity. The PW 12 /ZSM-5 based solid polyacid was a promising catalyst for the efficient FF production from biomass with high yield and easy separation.
研究领域:
生物化学
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催化化学
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产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2022
·
IF 5.876
Xiuli Shao,Siqi Wang,Youhui Zhou,Xuan Zhang,Haizhou Tian,Zheng Wang,Zhong-Yong Yuan,Huanting Wang
The ZSM-5 zeolite nanosheets are highly desired materials for catalytic reactions and membrane separation . Their synthesis depends on specially designed complex surfactants ; however, the high-cost limits their large-scale industrial production. Herein, the tailored synthesis of coffin-shaped multilamellar ZSM-5 composed of orderly stacked 2D nanosheets is carried out using cetyltrimethylammonium bromide (CTAB) as a structure-directing agent (SDA) in the presence of silicalite-1 seed sol. The morphology and b -axis thickness of nanosheets is controlled by adjusting the amount of silicalite-1 seed sol, CTAB/TEOS ratio, SiO 2 /Al 2 O 3 ratio, and synthesis time. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis indicate that the hydrophobic tail of CTAB acts as an inhibitor, effectively preventing the continuous growth along b -direction with an average thickness of 20–100 nm. This work highlights the role of silicalite-1 seed sol and CTAB in the orderly stacked sheets growth process. This crystallization strategy opens a facile and inexpensive approach for multilamellar ZSM-5 zeolite fabrication with 2D-nanosheets structures, and their practical applications in catalytic conversions of bulky molecules.
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
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Yang Jiao,Qi Wu,Wei Xu,Wei Lai,Luqi Xiao,Xue Mei,Hongjun Zhang,Shuangjiang Luo
Tailoring the microporous architecture of the precursors facilitates the gas separation performance in carbon molecular sieve (CMS) membranes. Herein, we report a facile strategy to tune the gas separation performance of CMS membranes through coordination between rare earth and imidazoles in the hierarchical triptycene-based polybenzimidazole (TPBI) precursor. By optimizing the pyrolysis condition and rare earth doping level, the resulting CMS membranes exhibited unprecedented H 2 and He permeabilities and high gas selectivities, and the TPBI-Yb 0.67 @700 CMS membrane exhibited a 3-fold increase in H 2 permeability and a 2-fold increase in H 2 /CO 2 selectivity compared to the TPBI-CMS@700 CMS membrane. It was demonstrated by the solution/diffusion coefficients and microporosity analysis that the enhancement of gas separation performance originated from the more pronounced hierarchically slit-like micropore structure, as well as the boosted diffusion and sorption selectivities. The TPBI-Yb 0.67 @700 membrane displayed a H 2 permeability of 8648 Barrer and a mixed-gas H 2 /CO 2 selectivity of 14.5 at 150 °C, far exceeding the experimental CMS upper bound.
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
危险品化学品经营许可证（带存储）