Catalysts
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2020
·Vol. 10
·期 4
·377
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IF 3.52
Wei Yu,Wenfeng Han,Yongnan Liu,Jiaqin Lu,Hong Yang,Bing Liu,Haodong Tang,Aimin Chen,Ying Li
BaClxFyas well as BaF2and BaClF catalysts were prepared by solid-state reaction at room temperature with Ba(OH)2as the precursor and NH4F/NH4Cl as the F and Cl sources. The catalysts were applied for the dehydrochlorination of 1-chloro-1,1-difluoroethane to vinylidene fluoride at 350 °C. The industrial manufacture of vinylidene fluoride (VDF) is carried out at 600–700 °C, whereas the BaClxFycatalysts provided a promising pathway to produce VDF at much lower temperatures. Unfortunately, the selectivity of VDF over BaF2decreased from 94% to 84% along with the deactivation of the BaF2catalyst monotonically. In the presence of small amounts of Cl in BaF2, stabilized selectivity was achieved. Over BaCl0.05F0.95, BaCl0.1F0.9and BaCl0.25F0.75, no decrease in VDF selectivity was observed. Clearly, the presence of small amounts Cl during solid-state preparation inhibited the growth of BaF2crystalline significantly. Far smaller particles were achieved. The particle size, or more precisely, the crystal size of the barium catalyst played a major role in the catalytic performance. In addition to the crystal growth, the presence of small amounts of Cl during catalyst preparation changed the chemical state of Ba, and therefore the adsorption and activation of the C–Cl bond for HCFC-142b were altered.Keywords:barium chlorofluoride;catalytic pyrolysis;barium fluoride;dehydrochlorination;1-chloro-1,1-difluoroethane;vinylidene fluoride
研究领域:
化学工程
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材料科学
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催化
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高影响因子
JOURNAL OF CHROMATOGRAPHY A
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2020
·
IF 4.049
Zhentao Li,Zhenkun Mao,Changjun Hu,Qiaoyan Li,Zilin Chen
Fluorous affinity means remarkably specific interaction between highly organic fluorides. This work aims to explore the potential of fluoro-functionalized stationary phase for the separation of organic fluorides by means of fluorous-fluorous interaction. Here, by using the Michael addition strategy between 1H,1H,2H,2H-perfluorodecanethiol (PFDT) and polydopamine (PD), a novel fluoro-functionalized stationary phase was synthesized for open-tubular capillary electrochromatography (OT-CEC). The PFDT@PD was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray Photoelectron Spectrometer (XPS). The PFDT@PD@capillary exhibited outstanding separation performance towards neutral compounds (such as alkylbenzenes and chlorobenzenes) and organic fluorides (such as fluorobenzenes and perfluoroalkyl methacrylates etc.) with high resolution and high separation efficiency by hydrophobic interaction and fluorous-fluorous interaction. In addition, the column shows good stability and reproducibility. The relative standard deviations (RSDs) of the retention time for intra-day (n = 5) and inter-day (n = 3) runs and between columns (n = 3) are less than 0.39%, 1.22% and 3.87%, respectively. This novel type of fluoro-functionalized stationary phase represents a great application potential in organic fluorides separation field.
研究领域:
分析化学
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材料科学
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PubMed
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
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2019
·Vol. 166
·期 12
·A2419
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IF 3.12
Xianhua Hou,Zishuai Zhang,Kaixiang Shen,Shikun Cheng,Qinyu He,Yumeng Shi,Denis Y. W. Yu,Ching-yuan Su,Lain-Jong Li,Fuming Chen
An anion flow battery has recently emerged as an option to store electricity with high volumetric energy densities. In particular, fluoride ions are attractive for these batteries because they have the smallest size among anions, which is beneficial for charge transport. To date, reported fluoride ion batteries either operate with an ionic liquid, organic electrolyte or solid-state electrolyte at high temperatures. Herein, an aqueous fluoride ion flow battery is proposed that consists of bismuth fluoride as the anode, 4-hydroxy-TEMPO (TEMPO) as the cathode, and NaF salt solution as the aqueous electrolyte. During the charging process, bismuth fluoride electrochemically releases fluoride ions with the formation of bismuth metal, while TEMPO captures the fluoride ions. A reversible and stable discharge capacity of 89.5 mAh g−1 was achieved at 1000 mA g−1 after 85 cycles. The fluoride ion battery possesses excellent rate performance. To the best of our knowledge, this is the earliest demonstration that fluoride ion batteries can work in aqueous solutions, which can be used for future clean energy applications.
研究领域:
能源科学
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材料科学
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高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2023
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IF 11.4
Mian Bao,Hongru Feng,Yuanyuan Zheng,Haiwei Luo,Cuirong Sun,Yuanjiang Pan
Perfluorooctane sulfonyl fluoride (PFOSF) and perfluorohexane sulfonyl fluoride (PFHxSF) were listed as persistent organic pollutants by the Stockholm Convention in 2009 and 2022, respectively. To date, their concentrations in environmental samples have not been reported due to the lack of sensitive methods. Herein, a novel chemical derivatization was developed for quantitative analysis of trace PFOSF and PFHxSF in soil by derivatizing them to the corresponding perfluoroalkane sulfinic acids. The method showed good linearity in the range from 25 to 500 ng L–1 with correlation coefficients (R2) better than 0.99. The detection limit of PFOSF in soil was 0.066 ng g–1 with recoveries in the range of 96–111%. Meanwhile, the detection limit of PFHxSF was 0.072 ng g–1 with recoveries in the range of 72–89%. Simultaneously, perfluorooctane sulfonic acid (PFOS) and perfluorohexane sulfonic acid (PFHxS) were also detected accurately without being affected by the derivative reaction. By applying this method in an abandoned fluorochemical manufacturing facility, PFOSF and PFHxSF were successfully detected at concentrations ranging from 2.7 to 357 ng g–1 and 0.23 to 26 ng g–1 dry weight, respectively. It is very interesting that 2 years after factory relocation, there still exists high concentrations of PFOSF and PFHxSF, which is of concern.
研究领域:
环境科学
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分析化学
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PubMed
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
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2018
·Vol. 44
·期 9
·5091-5105
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IF 1.674
Shi Xiang,Shi Hongxin,Wu Hongke,Shen HaiMin
A series of novel fluoroether-containing monomers has been designed and prepared based on the commercially available perfluoroalkyl ether acid fluoride. Treating acid fluoride with allyl alcohol, 2-hydroxyethyl methacrylate or N -allylmethylamine allowed for the direct formation of corresponding vinyl-containing fluorinated monomers. High yields of the fluorinated epoxy monomers could be obtained from acid chloride with glycidol; meanwhile, fluorinated diol was prepared from diethanolamine or 3-amino-1,2-propanediol. Moreover, fluorinated monoamine, fluorinated monoalcohol and fluorinated dichloride were also obtained. Most of these fluorinated monomers were liquid at room temperature and exhibited good solubility in common organic solvents.
研究领域:
有机化学
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材料科学
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高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2021
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IF 7.963
Min Yang,Xiaolei Zhang,Yicheng Yang,Qiang Liu,Long D. Nghiem,Wenshan Guo,Huu Hao Ngo
This study investigated the degradation of perfluorooctanoic acid (PFOA) on zerovalent iron-laden biochar (BC-ZVI) prepared by carbothermal reduction. Results show that over 99% PFOA can be removed by BC-ZVI in hydrothermal conditions under 240 °C within 6 h. The maximum defluorination rate of 63.2% was achieved after 192 h, and this outcome was significantly better than biochar (BC) and zero-valent iron (ZVI) alone. The short-chain perfluorinated compounds (PFCs) and perfluoroheptanal were detected in the liquid phase after degradation, suggesting that the degradation of PFOAs by BC-ZVI followed the Kobel decarboxylation process. XRD and SEM-EDS analyses strongly suggested that carbothermal reduction could avoid the agglomeration of ZVI loaded onto biochar, which helped make the PFOA degradation more efficient. The frontier molecular orbital theory calculated by density functional theory revealed there were two possibilities for ZVI loading on BC (edged or internal loading), while the edge loaded ZVI had a greater tendency to provide electrons for the defluorination of PFOA than internally loaded ZVI.
研究领域:
环境科学
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化学工程
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PubMed
高影响因子
APPLIED SURFACE SCIENCE
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2019
·
IF 5.155
Jiating Wen,Zhe Sun,Jun Xiang,Haojun Fan,Yi Chen,Jun Yan
A series of fluorinated waterborne polyurethane (FWPU) with various lengths of fluorinated side chains were synthesized by using different fluoro alcohol-terminated isocyanate trimer (F-HDIT) which prepared from hexafluoroisopropanol (HFIP), 2,2,3,3,4,4,5,5-octafluoropentanol (OFP), 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-1-octanol (TFO) and hexamethylene diisocyanate trimer (HDIT). The influences of fluorocarbon chains' length and fluorine content on the properties of FWPU, involving contact angle, surface energy of film and critical surface tension of emulsion were well-investigated in detail. The XPS result showed that the surface atom percentage of fluorine element of film increased from 0.58 for 6FWPU-5 to 28.19 for 13FWPU-20 with the escalation of F-HDIT content and the length of fluorocarbon lateral chain, which results in the water contact angle increment and surface energy reduction of FWPU films. Similarly, along with the increase of F-HDIT content and fluorocarbon side chains' length, the surface tension of FWPU emulsion exhibited a downtrend with the order of 13FWPU-20 (33.4 mNm −1 ) < 8FWPU-20 (36.5 mN·m −1 ) < 6FWPU-20 (36.9 mN·m −1 ) < FWPU-0 (40.0 mN·m −1 ). Besides, the enrichment of fluorocarbon chains can be deduced from AFM 3D morphology. The control sample FWPU-0 showed a relatively smooth surface while FWPU samples exhibited spike-like surface, indicating that the migration of fluorine side chains might increase the surface roughness of FWPU films.
研究领域:
材料科学
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化学工程
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2015
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IF 4.529
Bo Yang,Chaojin Jiang,Gang Yu,Qiongfang Zhuo,Shubo Deng,Jinhua Wu,Hong Zhang
The novel F-doped Ti/SnO 2 electrode prepared by SnF 4 as the single-source precursor was used for electrochemical degradation of aqueous perfluorooctanoic acid (PFOA). Higher oxidation reactivity and significantly longer service life were achieved for Ti/SnO 2 –F electrode than Ti/SnO 2 – X ( X = Cl, Br, I, or Sb) electrode, which could decomposed over 99% of PFOA (50 mL of 100 mg L −1 ) within 30-min electrolysis. The property of Ti/SnO 2 –F electrode and its electrooxidation mechanism were investigated by XRD, SEM–EDX, EIS, LSV, and interfacial resistance measurements. We propose that the similar ionic radii of F and O as well as strong electronegativity of F caused its electrochemical stability with high oxygen evolution potential (OEP) and smooth surface to generate weakly adsorbed OH. The preparation conditions of electrode were also optimized including F doping amount, calcination temperature, and dip coating times, which revealed the formation process of electrode. Additionally, the major mineralization product, F − , and low concentration of shorter chain perfluorocarboxylic acids (PFCAs) were detected in solution. So the reaction pathway of PFOA electrooxidation was proposed by intermediate analysis. These results demonstrate that Ti/SnO 2 –F electrode is promising for highly efficient treatment of PFOA in wastewater.
研究领域:
环境科学
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材料科学
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化学工程
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DOI
PubMed
高影响因子
Organic Chemistry Frontiers
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2017
·Vol. 4
·期 10
·1958-1961
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IF 4.955
Liyan Wang,Xiaohuan Jiang,Pingping Tang
The first example of a silver-mediated fluorination of alkyl iodides with the Ruppert–Prakash reagent (TMSCF3) as a fluorinating agent has been reported. This reaction is compatible with a variety of functional groups and proceeds under mild reaction conditions. Moreover, we demonstrate that the large surface area of CaF2 dramatically increased the reaction yield.
研究领域:
有机化学
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药物化学
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合成方法学
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氟化学
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转化医学
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DOI
高影响因子
Journal of Environmental Sciences
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2012
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IF 1.66
Baoxiu Zhao,Mou Lv,Li Zhou
Perfluorooctanoic acid (PFOA) is a new-found hazardous persistent organic pollutant, and it is resistant to decomposition by hydroxyl radical (HO) due to its stable chemical structure and the high electronegativity of fluorine. Photocatalytic reduction of PFOA with β-Ga 2 O 3 in anoxic aqueous solution was investigated for the first time, and the results showed that the photoinduced electron (e − cb ) coming from the β-Ga 2 O 3 conduction band was the major degradation substance for PFOA, and shorter-chain perfluorinated carboxylic acids (PFCAs, C n F 2n+1 COOH, 1 ≤ n ≤ 6) were the dominant products. Furthermore, the concentration of F − was measured by the IC technique and defluorination efficiency was calculated. After 3 hr, the photocatalytic degradation efficiency was 98.8% and defluorination efficiency was 31.6% in the presence of thiosulfate and bubbling N 2 . The degradation reaction followed first-order kinetics ( k = 0.0239 min −1 , t 1/2 = 0.48 hr). PFCAs (C n F 2n+1 COOH, 1 ≤ n ≤ 7) were detected and measured by LC-MS and LC-MS/MS methods. It was deduced that the probable photocatalytic degradation mechanism involves e − cb attacking the carboxyl of C n F 2n + 1 COOH, resulting in decarboxylation and the generation of C n F 2n + 1 . The produced C n F 2n + 1 reacted with H 2 O, forming C n F 2n + 1 OH, then C n F 2n + 1 OH underwent HF loss and hydrolysis to form C n F 2n+1 COOH.
研究领域:
环境科学
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材料科学
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PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2024
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IF 12.2
Xun Liu,Yufei Shu,Yu Pan,Guoshen Zeng,Meng Zhang,Chaoqun Zhu,Youmei Xu,Aling Wan,Mengxia Wang,Qi Han,Bei Liu,Zhongying Wang
The persistence and ecological impact of per- and poly-fluoroalkyl substances (PFAS) in water sources necessitate effective and energy-efficient treatment solutions. This study introduces a novel approach using cerium dioxide (CeO 2 ) electrodes enhanced with oxygen vacancy (O v ) to catalyze the defluorination of PFAS. By leveraging the unique affinity between cerium and fluorine-containing species, our approach enables adsorptive preconcentration and catalytic degradation at low oxidation potentials (1.37 V vs. SHE). Demonstrating high removal and defluorination efficiencies of perfluorooctanoic acid (PFOA) at 94.0% and 73.0%, respectively, our approach also proves effective in the environmental matrix. It minimizes the impacts of co-existing natural organic matter and chloride ions, crucial benefits of operating at lower oxidation potentials. The role of O v in CeO 2 is validated by both experimental results and density functional theory modeling, demonstrating that these sites can activate the C–F bond and substantially reduce the energy barriers for defluorination. Consequently, our CeO 2 -based method not only achieves defluorination efficiencies comparable to more energy-intensive techniques but does so while requiring less than 0.62 kWh/m 3 per order. This positions our approach as a promising, cost-effective alternative for the remediation of PFAS-contaminated waters, emphasizing its relevance and effectiveness in environmental remediation scenarios.
研究领域:
环境科学
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材料科学
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PubMed
高影响因子
JOURNAL OF CATALYSIS
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2018
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IF 6.759
Jian-Dong Song,Tong-Yang Song,Ting-Ting Zhang,Yun Wang,Meng-Fei Luo,Ji-Qing Lu
A series of supported V 2 O 5 /MgF 2 catalysts were prepared and tested for dehydrofluorination of 1,1,1,3,3-pentafluoropropane (HFC-245fa) to synthesize 1,3,3,3-tetrafluoropropene (HFO-1234ze). The addition of V 2 O 5 in MgF 2 resulted in up to 5-fold increase in HFC-245fa conversion (from 19.2 to 95.2%) and much enhanced catalyst stability. Characterization results revealed that the dehydrofluorination initiated on the MgF 2 support triggered the transformation of V 2 O 5 to vanadium oxyfluoride (VOF x ) species via the reaction between V 2 O 5 and HF, and such species were responsible for the improved activity as they had much higher turnover frequencies (TOFs) than the MgF 2 (0.762 s −1 v.s. 0.026 s −1 at 320 °C). The kinetic results indicated that the 3.1V 2 O 5 /MgF 2 had much lower activation energy (44.6 ± 1.9 kJ mol −1 ) than the MgF 2 (69.0 ± 0.8 kJ mol −1 ). Accordingly, reaction mechanism on the V 2 O 5 /MgF 2 catalyst was proposed, which included slow dehydrofluorination on MgF 2 and fast dehydrofluorination on the VOF x species.
研究领域:
催化化学
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材料科学
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环境化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）