JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Qian Zhao,Xin Li,Guangyuan Chen,Zeru Wang,Chuan Tan,Cheng Liu,Hao Zou,Jing Ma,Lin Zhu,Tao Duan
Effective capture of radioactive iodine from nuclear fuel reprocessing is of great importance for public safety as well as the secure utility of nuclear energy. In this work, a hydrophobic nanosheet silicalite-1 (NSL-1) zeolite with an adjustable size was developed for efficient iodine (I 2 ) and methyl iodide (CH 3 I) adsorption. The optimized all-silica zeolite NSL-1 exhibits an excellent I 2 uptake capacity of 553 mg/g within 45 min and a CH 3 I uptake capacity of 262 mg/g within 1 h. Benefiting from the reduced thickness and enhanced porosity, microporous NSL-1 possesses enhanced iodine adsorption capacity and fast adsorption kinetics , which is a considerable high value among inorganic materials . Unexpectedly, the remarkable characters of high hydrophobicity , acid-resistance and anti-oxidation endow it a higher iodine uptake capacity than traditional aluminosilicate zeolites. More importantly, the high uptake selectivity toward I 2 possessed by NSL-1 owing to its hydrophobic skeleton under simulated dynamic conditions. The low cost, facile and scalable synthesis of NSL-1 further highlights great prospects for applications in the nuclear industry. This work provides useful insights for designing efficient adsorbents for iodine capture .
研究领域:
材料科学
·
核能工程
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 65
·41070-41076
·
IF 3.108
Xin-ling Fu,Ming Zeng,Jian-bo Zhou,Chao Xu
A novel strategy for synthesizing silicalite-1 membrane by hydrothermal synthesis without organic template after coating the support with a mixture of modified cellulose and seeds was successfully proposed. The membrane possesses high ideal separation factors of H2 over various gases which is larger than the corresponding Knudsen diffusion coefficients. The selectivity of AcOH from AcOH/H2O mixtures can reach to 65 and stable for 180 h. The characterization results by XRD and SEM showed that the excellent performance can be attributed to both modified cellulose and the synthesis without organic template. Modified cellulose attracted more silicalite-1 nutrients to the support and assisted the synthesis of more compact silicalite-1 zeolite membrane. Calcination after synthesis was avoided, thus avoiding macrostructure defects appearing during the process of calcination.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Royal Society Open Science
·
2022
·Vol. 9
·期 11
·
IF 3.653
Jiangyi Yan,Yuting Cai,Rong Xu,Beifu Wang,Lihong Nie
The ability of membranes to separate oil vapour is affected by their permeance and selectivity. This study modifies polyether block amide (PEBA) composite membranes with a microporous zeolite, Silicalite-1, or a mesoporous zeolite, MCM-41. The results show that when PEBA composite membranes are modified with these zeolites, the selective layer of the composite membrane is coated more thinly, resulting in a higher flux of organic gas. Silicalite-1 increases the hydrophobicity of the membrane, which facilitates the adsorption of organic vapour on the membrane surface, thus improving the membrane selectivity. In the separation of oil vapour, both modified membranes can effectively increase the gas permeabilities and selectivities. The main mechanism governing gas transport in the MCM-41-modified membrane is Knudsen diffusion, so the selectivity for small molecules is improved more significantly. By contrast, the dissolution–diffusion mechanism is dominant in the Silicalite-1-modified membranes, which considerably increases the selectivity for large molecules.
研究领域:
材料科学
·
化学工程
·
膜技术
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2020
·
IF 4.551
Jun Yang,Ya-Xi Huang,Yuanming Pan,Jin-Xiao Mi
Researches on zeolite silicalite-1 have focused mainly on improving its performance, with little attention paid on green and economic synthesis. Herein, a novel route for green synthesis of pure silicalite-1 from the recycled mother liquor has been developed. This route starts from the hydrothermal reaction of natural quartz with NaOH to form a sodium silicate solution, which is then transformed into a silicic acid (H 2 SiO 3 ) gel by hydrochloric acid titration. Then the solid silicic acid (H 2 SiO 3 ) gel and fumed silica (SiO 2 ) are mixed with water under stirring to form a highly active slurry, which can be hydrothermally “dissolved” in a dilute NaOH aqueous solution. Using this slurry with a high SiO 2 /Na 2 O molar ratio of 5 : 1 as the silica source as well as tetrapropylammonium bromide (TPABr) as the organic template, MFI-type pure silicalite-1 has been successfully synthesized. After each synthesis, the mother liquor of centrifuged supernatant was recovered and recycled. The silica source and organic template were added to the recycled mother liquors for the synthesis of pure silicalite-1. The minimum TPABr/SiO 2 molar ratio needed to synthesize pure silicalite-1 in the initial run is 0.04 : 1. In comparison, only half the amount of the organic template is needed in subsequent runs with the recovered mother liquors. Through recycling, all reactants in the mother liquors were ultimately utilized without any waste, leading to not only effectively reducing the cost of silicalite-1 synthesis but also minimizing its environmental impact.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2022
·
IF 5.876
Yi Zuo,Yu Chen,Tonghui Li,Jiaojiao Yu,Hong Yang,Min Liu,Xinwen Guo
A bulky composite material, CaCO 3 @TS-1, was synthesized in a tetrapropylammonium bromide hydrothermal system by adding nanosized CaCO 3 particles of 60–80 nm to a titanium silicalite-1 (TS-1) synthesis gel. The macroporous TS-1 free of extraframework Ti was then obtained by the posttreatment of the CaCO 3 @TS-1 in HCl solution to remove CaCO 3 and extraframework Ti simultaneously. This study demonstrates that this new synthesis route, the acidity posttreatment, can produce a bulky TS-1 with volume-controllable intracrystal macropores. The crystallization mechanism of the macroporous TS-1 was studied systematically. The addition of CaCO 3 accelerates the crystallization of silicon source, and leads to the similar crystallization rates of silicon and titanium sources. Therefore, the formation of extraframework Ti was inhibited, and more Ti ions were inserted into the TS-1 framework. The catalytic performance of macroporous TS-1 was evaluated in the hydroxylation of phenol . An outstanding catalytic activity was obtained due to their enhanced diffusion property and reduced extraframework Ti.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2022
·
IF 5.876
Xiuxiu Ren,Huan Yu,Meng Guo,Rong Xu,Jing Zhong
A long alkyl chain-containing organosilica layer obtained from 1, 8-bis(triethoxysilyl)octane (BTESO) was used to modify silicalite-1 membranes via a sol−gel method to obtain bi-layered BTESO/silicalite-1 composite membranes on macroporous α-Al 2 O 3 supports for the recovery of diluted ethanol by pervaporation . Silicalite-1 zeolite membranes were hydrothermally synthesized using two seeding methods: those prepared using wet−rubbing seeding method exhibited larger separation factors than those obtained using the dip−coating method in the pervaporation of ethanol/water due to the thinner seed layer in the former. After modified with BTESO, the surface became smoother and denser with higher hydrophobicity , and the thickness of BTESO layer was approximately 300 nm on both types of membranes. In pervaporation, two types of silicalite-1 membranes unexpectedly showed similar performances after BTESO modification. Ethanol flux increased or was maintained while water flux decreased greatly for silicalite-1 membranes after BTESO coating with increasing sol concentrations, and a higher separation factor was attained without sacrificing ethanol flux. The long alkyl chains in BTESO and silanols reacted with hydroxyl groups in silicalite-1 provided flexibility and hydrophobicity for ethanol transport with minor resistance. The optimized 2.0% BTESO/silicalite-1 membranes synthesized using wet−rubbing method showed a maximum flux of 6.84 kg m −2 h −1 and separation factor of 24.6 with overall pervaporation separation index of 161 in the pervaporation of 5.0 wt% ethanol/water mixture at 60 °C.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
NANOTECHNOLOGY
·
2021
·Vol. 32
·期 47
·475708
·
IF 3.874
Qiu-Ping He,Yun Zou,Peng-Fei Wang,Xiao-ming Dou
Silicalite-1 zeolitic membranes have been successfully fabricated on the porous α-Al2O3 support by templated and template-free protocol, respectively, for vapor permeation separation of dichlorobenzene (DCB) isomers. After proving the high quality of the membranes by single gas permeation (He and SF6) performance, the vapor-permeation of DCB isomers over two types of the silicalite-1 membrane was then investigated. The separation results clearly indicated that under the lower partial pressure and higher temperature, the effect of DCB isomer adsorption on the permeance could be kept at a sufficiently low level and sharp selectivity become more important. Thus, high p-DCB selectivity could be achieved. Comparatively, the template-free silicalite-1 zeolite has a much higher p-DCB selectivity due to the relatively fewer inter-crystalline gaps. Under certain separation conditions, the highest selectivity of p-DCB for p-/m-DCB and p-/o-DCB binary systems could reach 165 and 113, respectively.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Catalysts
·
2025
·Vol. 15
·期 6
·584
·
IF 4
Benlong Yu,Tao Wang,Chao Xiao
This study describes a monolithic silicalite-1 catalyst support designed for tritium oxidation reactions under humid conditions. Monolithic molecular sieves (sil-s) were fabricated by converting silica binders to silicalite-1 through secondary crystallization (175 °C, 24 h). In addition to the binder conversion to silicalite-1, some recrystallization of starting silicalite-1 (sil) results in higher crystallinity, lower concentration of silanol defects, and higher hydrophobicity. With the addition of 2% platinum, Pt/sil-s exhibited better stability under humid conditions, showing only 0.01%/min conversion decay over 800 min. This work has demonstrated a moisture-resistant Pt catalyst for tritium oxidation in fusion energy systems.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2025
·
IF 4.8
Jin Guo,Xueying Bai,Xianquan Li,Jifeng Pang,Lele Feng,Yujia Zhao,Yang Su,Shimin Liu,Chaoqian Liu,Mingyuan Zheng
Copper(Cu)-based catalysts are highly promising candidates for ethanol dehydrogenation owing to their exceptional activity in cleaving O-H and C-H bonds. Nevertheless, their widespread application is hindered by challenges such as rapid deactivation and complex preparation procedures. Herein, inspired by the deactivation mechanism of Cu/MFI (silicalite-1) catalysts, two strategies, i.e., using mixed solvents for impregnation and enriching silanol nests of MFI to anchor Cu particles, were used to synthesize Cu/MFI-R catalysts with high stability and activity. The mixed solvent approach reduces the surface tension of solvents, enhancing the uniform dispersion of Cu over the hydrophobic surface of MFI. Subsequently, a MFI-R support with abundant silanol nests was synthesized via optimizing hydrothermal conditions, as confirmed by reaction results and characterizations of FT-IR, UV-Vis and solid NMR. By combining these strategies, Cu/MFI-R catalysts were synthesized for ethanol dehydrogenation, achieving > 90 % ethanol conversion and 95 % acetaldehyde selectivity over the 600 h time on stream test. This work provides a very promising scalable approach for the design of stable Cu-based catalysts in hydrogen-related reactions.
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Honglin Yu,Mengqi Liu,Guodong Zhang,Fei Wang
As the key to open the Pandora’s box of gas efficient capture, water-based porous liquids have doubled the popular attention. Nevertheless, the synthesis of water-based porous liquids is a significant challenge due to the inherent limitation in the wettability of nanoporous hosts. In this work, Silicalite-1 was prepared by hydrothermal synthesis, based on which a water-based porous liquid of S-1-PL was successfully prepared, and CH 4 capture in the porous liquid via adsorption-absorption synergistic approach was evaluated. It was demonstrated that S-1-PL exhibited excellent stability and flowability, with a pore opening ratio up to 90 %. CH 4 capture capacity in S-1-PL with the solid content of 15 wt% was 0.57 mol/L, which was 2.6 times that in pure water system, demonstrating excellent CH 4 physisorption performance. When the adsorption-absorption synergistic approach was employed, CH 4 capture capacity increases to 1.88 mol/L with an increase by 229.8 %. In addition, a hydrate nano-promoter of −SO 3 - @PSNS was prepared to enhance hydration efficiency, which resulted in a notable enhancement in the hydration conversion rate, and it increases from 12.54 % to 61.99 % in the system of S-1-PL 15wt% , giving rise to a significant increase in CH 4 capture to 6.22 mol/L, which is 12.67 times that in the system of −SO 3 - @PSNS solution. These findings provide clear evidence for the first time on the exceptional adaptability of water-based porous liquid for the capture of CH 4 by adsorption-absorption synergistic approach, offering a new strategy for the emission reduction of CH 4 .
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Frontiers in Chemical Engineering
·
2026
·
IF 2.6
Gideon Abaidoo Ocran,Bosong Zhang,Yi Zuo,Huali Tan,Gudan Li,Hong Yang,Chunshan Song,Xinwen Guo
The epoxidation of allyl alcohol with H2O2 over titanium silicalite-1 (TS-1) is an environmentally friendly route for producing glycidol. However, the catalytic activity and stability of TS-1 is not satisfactory. In this study, strip-shaped TS-1 was hydrothermally treated by TPAOH solution, change theTi coordination states and diffusion property, thereby enhancing its catalytic performance. The influences of TPAOH concentration and treating time on the physical chemical property and catalytic performance were studied systematically. It was found that the SiO2 agglomerant was dissolved and crystallized during the treatment, resulting in an increased Si content on the external surface. The tetrahedrally coordinated Ti was transformed to pentahedrally and octahedrally coordinated Ti, which possess higher catalytic activity for selective oxidation. The treatment also leads to the formation of cavities in the TS-1 crystals, which can shorten the diffusion pathway of substates and improve the diffusion property. Both the chemical property and microstructure enhance the catalytic activity for allyl alcohol epoxidation.
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2023
·
IF 5.2
Zilin Wang,Tao Wang,Long Mu,Zhilin Chen,Lishuang Hu,Chao Xiao
Understanding of the main factors affecting the hydrothermal stability of zeolites is vital for the application of zeolites in catalysis and separation. Although incorporation of extra-framework metal cations is an important stagey to improve the hydrothermal stability of Al-rich zeolites, how these metal cations affect the hydrothermal stability of high-silica zeolites is not well understood. In this work, the effects of residual alkali cations on the hydrothermal/thermal stability of silicalite-1, a pure-silica MFI-type zeolite, is explored. We show that the alkali impurities from commercial tetrapropylammonium hydroxide (TPAOH) are not negligible; the concentration and type of residual alkali cations dictate the hydrothermal/thermal stability of silicalite-1. Above a certain concentration (∼0.3–0.5 wt%), the alkali cations can lead to less silanol defects but much poorer hydrothermal/thermal stability. Below this concentration, the degrading effect is negligible. Removal of the alkali cations by proton exchange improves the stability significantly. Steaming (hydrothermal treatment) has two opposite effects on the silicalite-1 crystal structure: destruction by hydrolysis and perfecting by healing the defects. For silicalite-1 with considerable amounts of alkali cations, the destruction effect predominates; while the perfecting effect predominates for silicalite-1 with low alkali contents.
研究领域:
材料科学
·
化学工程
·
催化
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）