Molecular Catalysis
·
2025
·
IF 4.9
Kai Zhang,Shuwei Chen,Zhaohui Guo,Yingxiong Wang,Yan Qiao
As a renewable resource, the catalytic conversion of xylose has attracted much attention. The epimerization of xylose to lyxose is an important way to obtain the rare sugar lyxose. Current approaches to xylose epimerization encounter several challenges, including the requirement for high temperatures, the use of costly catalysts and a propensity for side reactions that favor the formation of ketoses. CaCl 2 is an environmentally friendly and naturally abundant metal salt that can act as a Lewis acid in catalytic processes. Herein, we demonstrate that CaCl 2 and Et 3 N work synergistically to achieve 68 % lyxose yield under mild conditions. Compared to conventional approaches, which often require harsh conditions or expensive catalysts, our system demonstrates a cost-effective and selective strategy. Moreover, through a combined experimental and computational approach (NMR, isotope tracing and DFT), we provide unprecedented mechanistic insights into the role of calcium complexation in facilitating epimerization. Complexation between xylose and calcium ion was confirmed by NMR titration and Diffusion Ordered NMR Spectroscopy (DOSY-NMR). Isotope experiments further demonstrated that the C1-C2 migration caused the turnover of the hydroxyl group at C2 in the presence of calcium ions. The frontier orbital analysis and deprotonation energy calculation showed that the hydroxyl group at C1 had the lowest deprotonation energy, which initiated the ring-opening process. The DFT calculations reveal that the calcium ions preferentially complex with the hydroxyl groups of xylose, thereby reducing the energy barrier for the C1 proton dissociation and facilitating the epimerization. These findings offer a new perspective on xylose epimerization with Ca-based catalyst.
研究领域:
生物化学
·
催化化学
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Miao-Miao Jia,Si-Yuan Yang,Ke-Ke Chen,Pan-Pan Zhang,Wei Shao,Zhen Chen,Zi-Meng Xu,Qing-Yun Wu,Yi Li,Ming Xue
Thin-film composite (TFC) reverse osmosis (RO) membranes, fabricated by interfacial polymerization, have achieved significant success in addressing the global water scarcity. Over the past three decades, the camphor sulfonic acid (CSA)/triethylamine (TEA) has been widely used in fabrication of TFC RO membranes. However, the mechanism of this unique formula remains elusive and contentious. In this work, for the first time, deciphering that introducing CSA/TEA into the aqueous phase has negligible impact on the selective polyamide (PA) layer but facilitate the aqueous solution impregnating of porous polysulfone (PSf) support. Specifically, the acidic CSA significantly hinders amine diffusion yet preserves the porosity of the PSf support during high-temperature curing. TEA is essential in modulating the pH changes and balancing the monomer diffusion rate that results from CSA. The COMSOL simulations have further elucidated that the presence of an aqueous solution within the porous support can mitigate the thermal expansion of the PSf, consequently inhibiting the shrinkage of surface pores. The TFC membrane demonstrated a substantial improvement in water permeance due to the preservation of its pore structure. The obtained TFC membrane demonstrated an exceptional NaCl rejection of 99.3 % and a high water flux of 76.8 L m –2 h −1 (2000 ppm NaCl, 15.5 bar), exceeding that of the state-of-the-art TFC RO membranes. Moreover, the RO membrane manifested with long-term stability and good fouling resistance. The mechanistic insights have important implications to more efficient membrane-based desalination and water reuse, thereby reducing energy consumption and minimizing environmental carbon footprint.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2024
·
IF 8
Shenman Yao,Dehua Wang,Jiahao Li,Jianxian You,Yulin Zhu,Wufei Gong,Keng Xu,Yan Liang,Yanxing Yang,Yong Yang
Crystal facets engineering emerges as a potent strategy for modulating the surface properties and gas sensing performance of semiconductor metal oxides. However, related studies have primarily focused on conventional binary metal oxides gas sensing materials, while few studies have investigated the crystal facets-dependent gas sensing activity of recently developed ternary metal oxides. Herein, the effect of crystal facets on the gas sensing activity of Aurivillius-type layered perovskite structure material Bi 2 MoO 6 was studied. It was shown that Bi 2 MoO 6 nanosheets with {001} crystal facets exhibited significantly enhanced gas sensing activity with a high response value of 72 (R a /R g ) towards 100 ppm of triethylamine at relatively low working temperature of 250 °C, which was about 10 times higher than that of Bi 2 MoO 6 nanosheets with {010} crystal facets. The gas mechanism was elucidated at the atomic and electronic levels through first principles calculation combined with experimental characterization. On the one hand, the synergistic effect of Mo/Bi bimetallic sites makes the adsorption/charge transfer between {001} facets and triethylamine much stronger. On the other hand, {001} facets have abundant chemically adsorbed oxygen and oxygen vacancy on the surface, which act as the active species in gas sensing. These results not only significantly broaden the application scope of Aurivillius-type layered perovskite structure materials in the realm of gas sensing, but also provide important guidance for the study of gas sensing mechanism in ternary metal oxides.
研究领域:
材料科学
·
气体传感技术
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Zhengdao Li,Yan Xiong,Dongqin Bi,Qi Liu,Chuanyun Yang,Jia Zhang
To optimize the structure and composition of the metal oxide semiconductor is one of effective approaches to improve its gas-sensing performance. In this paper, Zn 2 SnO 4 solid octahedrons were first synthesized by a hydrothermal method , then converted to hollow structures with a shape preserved through a simple and practical acid etching process. Ultimately, the hierarchical ZnSnO 3 /Zn 2 SnO 4 hollow composite with porous structure was designed and prepared by in situ growth of ZnSnO 3 nanosheets on the surface of Zn 2 SnO 4 hollow octahedrons in the seed mediated wet-chemical way. It was found that through the structure evolution from solid octahedron to hollow structure, the sensitivity of gas sensor toward triethylamine (TEA) was visibly improved. Significantly, superior TEA-sensing properties, such as lower optimal working temperature, higher sensitivity, wider linear response range, more rapid response/recovery speed and more excellent selectivity were further achieved by decorating Zn 2 SnO 4 hollow octahedrons with ZnSnO 3 nanosheets. It was remarkable that the sensor based on hierarchical ZnSnO 3 /Zn 2 SnO 4 porous hollow octahedrons displayed long-term stability to TEA and anti-humidity property, suggesting its potential practical applications in detection of highly toxic TEA. The improved sensing mechanism on the strength of structure and composition evolution for the gas sensor was discussed in detail.
研究领域:
材料科学
·
传感器技术
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2019
·
IF 2.29
Jian Wang,Yongqin Du,Cunbin Du,Anli Xu,Ganbing Yao,Hongkun Zhao,Xuedong Zhu,Xuhong Guo
Physical properties like density, viscosity, refractive index and conductivity of switchable hydrophilicity solvent (SHS) systems (triethylamine (TEA), water, and carbon dioxide) as a function of concentration at different temperatures ranging from 283.15 K to 308.15 K have been determined. These data have been used to calculate apparent molar volume, limiting apparent molar expansibility of solute and the relative viscosity of the studied solutions. The viscosity coefficients B have been determined from the Jones-Dole equation. The limiting apparent molar volumes and experimental slopes ( A v ) derived from the Masson equations have been interpreted in terms of solute-solute and solute-solvent interactions. From the volumetric and viscometric data, the structural effect of TEAH-bicarbonate salt in aqueous solvent has been discussed.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2023
·Vol. 25
·期 16
·6297-6305
·
IF 9.8
Zhaohui Guo,Christian Marcus Pedersen,Honghong Chang,Yingxiong Wang,Yan Qiao
As a renewable source, fructose is of great significance in biomass conversion and food industries. Currently, most of the chemo-catalysts studied, with glucose as a substrate, are limited by the thermodynamic equilibrium of the reaction, resulting in the maximum yield of fructose of approximately 30–40%. The similar chemical structures and physical properties of monosaccharides bring another challenge for the separation of fructose from the reaction mixture. In this study, the combination of CaCl2 and Et3N was found to alter the thermodynamic equilibrium and promote fructose separation. The reaction parameters were optimized and up to 78% fructose yield could be obtained. The pathways of the isomerization reaction were found to involve both intramolecular hydride shift and an enediol intermediate mechanism, and the former was major. It could be speculated reasonably that Ca2+ played a key role in glucose conversion and interacted with glucose at its C1 and C2 positions, and Et3N interacted with Cl− while providing an alkaline environment. The formation of the α-fructofuranose’ complex, from Et3N, CaCl2 and α-fructofuranose, could shift the equilibrium of glucose isomerization towards fructose formation. According to the diffusion-ordered spectroscopy (DOSY) NMR results, the strong complexation slowed down the diffusion rate of the α-fructofuranose’ complex, allowing it to gradually precipitate, and hence drove the reaction equilibrium towards the desired fructose. The precipitate was filtered from the reaction mixture and processed further to obtain high-purity fructose in 45% isolated yield. Moreover, the filtrate containing solvent and reagents obtained in the separation process could be recycled.
研究领域:
生物化学
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食品科学
·
生物质转化
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Xuehua Chen,Chao Qin,Zicheng Zheng,Hanwen Chi,Zhizhen Ye,Liping Zhu
Gas sensors with good repeatability and controllable fabrication method are extremely desired for practical applications. Co-MOF-derived Co 3 O 4 is a promising gas-sensing material candidate because of its large surface area, ultrahigh porosities, and abundant oxygen defects. However, the advantages of Co-MOF precursor were limited by the traditional sensor fabrication methods. Moreover, the high resistance and poor surface activity of Co 3 O 4 resulted in low gas-sensing performance at room temperature (RT). To overcome these challenges, in-situ sensors based on Co 3 O 4 porous films with controlled nanoscale thickness were directly prepared on ceramic substrates by using Co-MOF films as precursors. To further improve the conductivity, SnO 2 catalytic overlayers were introduced on top of Co 3 O 4 sensors to construct SnO 2 /Co 3 O 4 bilayer sensors, which were promising for triethylamine (TEA) detection at RT. As a result, the optimized SnO 2 /Co 3 O 4 sensor exhibited a fast response/recovery rate (11 s/16 s), high selectivity, and a satisfactory sensitivity (150%) to TEA at RT. The enhanced gas-sensing performance could be attributed to the unique bilayer structures, improved conductivity, and synergistic effects of the SnO 2 catalytic overlayers and Co 3 O 4 sensing layers.
研究领域:
材料科学
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化学传感器
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Lin Wang,Haili Huang,Dongdong Zhang,Hung-Chun Wu,Meiling Li,Huilin Hou,Weiyou Yang,Xuhui Yu,Zonghua Wang
Triethylamine (TEA) is a typically volatile organic compound that poses significant environmental and health risks, due to its high toxicity and volatility. Currently, the exploration of TEA sensors based on semiconductor ZnO is still suffered by their intrinsically low sensitivity, slow response/recovery times, and poor selectivity. Herein, we develop the highly-sensitive TEA sensors based on rationally-designed Co 3 O 4 /ZnO p-n heterojunctions, in which the clustered Co 3 O 4 are incorporated into porous ZnO nanosheets. As a result, at the given operating temperature of 260 °C, the as-constructed sensors exhibit an overall enhanced performance with an excellent response of 140.5 to 100 ppm TEA, swift response/recovery times of 6/60 s and high selectivity, representing their promise toward practical applications in advanced TEA sensors.
研究领域:
材料科学
·
环境科学
·
化学传感器
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2024
·Vol. 149
·期 10
·4827-4838
·
IF 3
Li Weilong,Zhang Fengyan,Li Xiaoquan,Hu Jiwen,Gui Xuefeng,Lin Shudong
Epoxy acrylate is produced by esterifying epoxy resin and acrylic acid through a ring-opening reaction. This process is highly exothermic and can be challenging to control gel formation. The thermal hazards of epoxy acrylate preparation were evaluated in this study by investigating the ring-opening esterification reaction between acrylic acid (AA) and bisphenol A epoxy resin (E-51) catalyzed by triethylamine (TEA). The heat release during the reaction process was analyzed using a reaction calorimeter (RC1 mx ) to simulate industrial conditions. Increasing the TEA catalyst content from 0.3 to 1.0 mass% resulted in a significant rise in reaction conversion from 75.35 ± 0.10% to 98.44 ± 0.10%. Differential scanning calorimetry (DSC) and accelerating rate calorimeter (ARC) were used to examine the thermal runaway process during epoxy acrylate synthesis. Increasing the TEA content from 0.3 to 1.0 mass% decreased the initial reaction temperature from 60.16 ± 0.62 to 45.33 ± 0.40 °C and the critical temperature of side reactions from 153.71 ± 1.51 to 117.85 ± 1.19 °C. The severity of the runaway was classified as medium at process temperatures of 80–110 °C. This study highlights the importance of considering reaction conditions to prevent uncontrolled reactions during epoxy acrylate synthesis, providing valuable insights for industrial epoxy acrylate preparation.
研究领域:
化学工程
·
安全科学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2024
·
IF 4.3
Junyao Li,Ruixiang Li,Chuanye Sang,Mingji Xu,Chunhua Luo,Hui Peng,Hechun Lin
Dehydration of layer metal hydroxides at controlled annealing temperatures is an efficient strategy for regulating the material properties. In this work, we studied the dehydration process of α-Co(OH) 2 with flower-like nanostructure under various conditions and explored their gas sensing application. Stable dehydrated α-Co(OH) 2 obtained by solidification in air at 140 °C, exhibits specific selective low-temperature gas-sensing behavior for Et 3 N. The response to 50 ppm Et 3 N was up to 9.52 at 140 °C operating temperature with short response and recovery time. The sensor is the high reversibility and the excellent reproducibility with ppb level detection limit. The partial oxidation of the dehydration α-Co(OH) 2 in the air has a significant impact on the sensing performance. The large specific surface area of the dehydration α-Co(OH) 2 affords rich reactive sites for both reaction and adsorption of Et 3 N molecules. This research provides a new solution for building low-temperature high-performance amine sensor.
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
Journal of Energy Storage
·
2024
·
IF 8.9
Wenxia Hu,Shimin Huang,Shenggong He,Yiran Zheng,Weishan Zhou,Haixia Cui,Hadia Noor,Xianhua Hou
Aqueous zinc ion battery will be the next-generation energy storage in prospect. Nevertheless, stern parasitic reactions occur on Zn anode at high temperatures, which results in extremely poor zinc anode reversibility. Herein, innovating a trace of triethylamine (TEA) antisolvents considerably resolves foregoing problems; TEA progressively interrelates with free water and coordination water, which diminishes water activity and is conducive to the destruction of Zn 2+ solvation sheath under high temperatures (80 °C). Furthermore, TEA antisolvent electrolyte facilitates uniform Zn 2+ deposition, lessens hydrogen evolution corrosions and eliminates side reactions as far as possible. In the hybrid antisolvent electrolyte, the symmetric Zn/Zn batteries can sustain comparatively longer cycling lifespan of 4000 h at 3 mA cm −2 , 1 mAh cm −2 than that of 135 h without TEA antisolvent. Not only has the Coulombic efficiency made up to 99.95 % in Zn/Cu asymmetric cell over 1600 cycles as well as 94.1 % over 100 cycles at 80 °C, but the Zn/MnO 2 full batteries have also performed constantly for >1000 cycles, showing a 79.03 % capacity sustenance proportion when the current density reached 5 A g −1 . This work opens up a brand-new prospect for high reversible zinc anode and dendrite-free aqueous Zn ion batteries utilizing antisolvent electrolytes.
研究领域:
能源存储技术
·
电化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2018
·Vol. 11
·期 12
·2431
·
IF 2.467
Xingang Li,Jinjian Hou,Hong Sui,Lingyu Sun,Lin Xu
In this study, SHT (switchable-hydrophilicity triethylamine, [Et3NH]·[HCO3]) has been synthesized and instrumentally characterized by Fourier transform–infrared spectroscopy (FTIR) and13C nuclear magnetic resonance (NMR). The operational synthesis conditions of SHT were optimized and determined at 25 °C, Et3N/H2O volume ratio of 1:2 and CO2injection rate at 300 mL/min. When it was used to extract heavy oil from unconventional oil ore, it was found that it could break maltenes-in-water emulsions. When asphaltenes were present in the oil phase, it was observed that SHT could cooperate with asphaltenes. These results indicated that SHT works with asphaltenes, leading to synergistic effects in stabilizing oil–water (o/w) emulsions.Keywords:switchable-hydrophilicity triethylamine (SHT);synergistic effect;emulsions stabilization;asphaltene
研究领域:
化学工程
·
石油科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）