FUEL
·
2024
·
IF 6.7
Zhenfeng Sun,Kaiqiang Zhao,Chen Wang,Jie Li,Haisheng Xu,Chao Yang
Presulfiding agents are widely used in oil refining and chemical industry, how to produce safe and efficient presulfiding agent by more environmentally friendly synthesis process are still problems to be solved. In this study, the organic polysulfide FSA-55 was synthesized by a practical one-pot process using isobutene and sulfur as raw materials and organic amine as a catalysts. The product components were analyzed and the possible catalytic reaction pathways in the thermal conversion of sulfides were elucidated. The amine catalysts showed a catalytic activities in inducing the ring opening of the cyclic molecular structure of sulfur at high temperature, thereby releasing the reactive sulfur radicals, which react with unsaturated double bonds through addition reactions. Different molecular structures of polysulfide were generated through molecular rearrangement and cyclization reactions. The suitability of the product as a presulfiding agent was investigated by analyzing the thermal properties and studying the presulfiding effect on hydrogenation catalysts. The polysulfide has a wide decomposition temperature range (100–260 °C), which can effectively avoid the occurrence of concentrated exothermic phenomena during presulfiding of hydrogenation catalysts. The presulfiding degree of the catalysts can reach 58.32%, which shows the great potential of oil processing as a presulfiding agent.
研究领域:
石油化工
·
催化化学
✓ 已验证
DOI
高影响因子
BIOMACROMOLECULES
·
2021
·
IF 6.988
Zhiqing Liu,Wei Yu,Wenbo Sheng,Rui Li,Helin Guo,Xiantao Feng,Qian Li,Rongjie Wang,Wei Li,Xin Jia
A facile and general strategy for preparing uniform and multifunctional polyphenol-based colloidal particles through amine-catalyzed polymerization-induced self-assembly is described. The size and interfacial adhesion of polyphenol spheres can be easily controlled over a wide range via adjusting the concentration of the cosolvent and monomer. Moreover, the polyphenol spheres showed excellent thermal and chemical stability and highly active properties and could efficiently deplete the reactive oxygen species (ROS), which are helpful for in vivo ROS regulation for inflammatory therapeutic. The accessible and versatile method provides a feasible way for the rational engineering of multifunctional polyphenol spheres, which have great potential in many fields.
研究领域:
材料科学
·
生物医学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2014
·Vol. 5
·期 8
·5674-5679
·
IF 3.708
Gang Wang,Li Peng,Yaochen Zheng,Yanqin Gao,Xuedong Wu,Tianhui Ren,Chao Gao,Jin Han
We describe a novel triethylamine catalyzed S → O acetyl migration reaction for yielding thiol compounds under mild conditions through the formation of a transitional 5-membered ring. A series of epoxy compounds have been transformed into their thiol counterparts which could be used for construction of topological and functional sulfur-containing polymers. The one-pot two-step processes including the S → O acetyl migration and the following thiol-click reactions avoided separation of thiol intermediates. Applying these processes on a new-type latent polythiols overcomes crosslinking problem usually met in preparation of multithiol compounds due to the formation of disulfide bonds.
研究领域:
化学
·
材料科学
✓ 已验证
DOI
高影响因子
Advanced Composites and Hybrid Materials
·
2018
·Vol. 2
·期 1
·51-69
·
IF 0
Shen Liang,Tian Lian,Zuo Jian,Zhang Xuan,Sun Shipeng,Wang Yan
A desirable membrane with high separation performance, excellent antifouling properties, and chemical stability is important to the advance of forward osmosis (FO) technology in the wastewater treatment and desalination processes. In this work, three different tertiary amines, i.e., tri-ethylamine (TEA), tris(2-aminoethyl) amine (TAEA), and hexamethylenetetramine (HMTA), are employed as catalysts to accelerate the interfacial polymerization (IP) reaction for constructing the PA layer with optimized properties and performance of the resulting membranes. For the first time, the effect of different tertiary amines on the microstructure, morphology, and surface properties of formed PA layers, as well as the separation performance, fouling, and chemical resistance of the resulting TFC membranes, are studied systematically with various characterization techniques. As compared with the control membrane, modified membranes exhibit obviously improved separation performance and greater potential in the desalination process. Furthermore, modified membranes also exhibit improved fouling resistance and chemical stability. Therefore, the tertiary amine modification of TFC membranes may shed a new light for their future applications in harsh conditions.
Graphical abstract
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
Journal of Chemical Information and Modeling
·
2024
·
IF 5.6
Xu Li,Haoliang Zhong,Haoyu Yang,Lin Li,Qingji Wang
Nucleophilic index (NNu) as a significant parameter plays a crucial role in screening of amine catalysts. Indeed, the quantity and variety of amines are extensive. However, only limited amines exhibit an NNu value exceeding 4.0 eV, rendering them potential nucleophiles in chemical reactions. To address this issue, we proposed a computational method to quickly identify amines with high NNu values by using Machine Learning (ML) and high-throughput Density Functional Theory (DFT) calculations. Our approach commenced by training ML models and the exploration of Molecular Fingerprint methods as well as the development of quantitative structure–activity relationship (QSAR) models for the well-known amines based on NNu values derived from DFT calculations. Utilizing explainable Shapley Additive Explanation plots, we were able to determine the five critical substructures that significantly impact the NNu values of amine. The aforementioned conclusion can be applied to produce and cultivate 4920 novel hypothetical amines with high NNu values. The QSAR models were employed to predict the NNu values of 259 well-known and 4920 hypothetical amines, resulting in the identification of five novel hypothetical amines with exceptional NNu values (>4.55 eV). The enhanced NNu values of these novel amines were validated by DFT calculations. One novel hypothetical amine, H1, exhibits an unprecedentedly high NNu value of 5.36 eV, surpassing the maximum value (5.35 eV) observed in well-established amines. Our research strategy efficiently accelerates the discovery of the high nucleophilicity of amines using ML predictions, as well as the DFT calculations.
研究领域:
化学信息学
·
计算化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF CATALYSIS
·
2021
·
IF 7.92
Xixi Liu,Yanxin Wang,Bo Li,Bing Liu,Wei Wang,Nian Xiang,Zehui Zhang
The catalytic acceptorless dehydrogenation of primary amines into imines and H 2 represents one of the most important organic transformations, and the in-situ utilization of the generated H 2 for chemical reduction reactions has never been reported in previous research. Herein, nitrogen-doped carbon supported nickel catalysts (abbreviated as Ni/NC-T, where T represents the pyrolysis temperature) were facilely prepared by the simple pyrolysis process, and the Ni/NC-600 catalyst demonstrated excellent catalytic performance towards the tandem reaction of the dehydrogenation of primary amines into imines and the subsequent hydrodeoxygenation of sulfoxides into sulfides using the in-situ released H 2 , affording high to quantitative yields. The developed methods demonstrated some advantages such as the use of heterogeneous non-noble metal catalysts with low cost and high stability, and the in-situ utilization of generated H 2 with high atom efficiency.
研究领域:
有机化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 5
·799
·
IF 3.9
Tao Wang,Jie Li,Hanwen Yan,Guoliang Zhang,Shifeng Li
Methacrolein (MAL) is an important intermediate extensively used in the manufacture of methyl methacrylate and other materials (polymers and resins). In this study, a series of secondary amines/acids were explored as catalysts for the condensation of formaldehyde and propionaldehyde to prepare MAL. It was found that the structure of the amines and acids directly affected the yield of MAL. The effect of the catalyst was closely related to the nucleophilicity of the amines as well as the steric hindrance effect, while acids also played a role as co-catalysts. Dibutylamine acetate was selected as the catalyst after investigation. The catalytic performance of the system was systematically studied by a series of single-factor experiments, including stirring rate, temperature, reaction time, acid/amine ratio, and the solvent, and the optimized reaction conditions were obtained. In the optimum condition, the yield of MAL was up to 97.3%. Kinetic experiments were performed for the condensation of formaldehyde and propionaldehyde to MAL, and the activation energies, reaction orders, and rate-limiting step of the reaction were determined. The results indicate that the decomposition of the Mannich base is a rate-limiting step.Keywords:methacrolein;aldol condensation;Mannich reaction;kinetics
研究领域:
有机化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Ling Zhou,Yaoyu Zhang,Yue Liu,Zhongbiao Wu
This work investigated the reaction behaviors of diethylamine (DEA) catalytic oxidation on various Cu-based catalysts with different supports (TiO 2 , HZSM-5(27), HZSM-5(130) and S-1). It was found that the acidic environment of catalysts greatly influenced reaction pathways of DEA oxidation. On Cu 5 /TiO 2 catalyst mainly with Lewis acidity, DEA preferentially dissociated through a two-step dehydrogenation to produce acetonitrile and ethylene, while on Cu 5 /HZSM-5(27) catalyst with strong Brønsted acidity, DEA could directly decompose into ethylamine and ethylene via N-C cleavage. Both pathways existed simultaneously over Cu 5 /HZSM-5(130) with decreased Brønsted acidity. Thereafter, acetonitrile could be further oxidized on the Cu 5 /TiO 2 catalyst to generate a large amount of NO x via NCO(a) intermediates over-oxidation, while ethylamine on Cu 5 /HZSM-5 samples would convert to acetamide and then produced N 2 and CO 2 . The Cu 2+ species due to enriched Brønsted acid sites in Cu 5 /HZSM-5 catalysts ensured excellent N 2 selectivity via internal SCR mechanism. Additionally, the strong Brønsted acidity of Cu 5 /HZSM-5(27) could induce the polymerization of carbonaceous intermediates and thereby resulted in severe coke deposition. As for Cu 5 /HZSM-5(130) and Cu 5 /S-1 with relatively lower Brønsted acidity and reducibility would release some unwanted gas-phase by-products like ethyl-isocyanate. This work provided useful guidance for designing NVOCs catalysts with high activity and less toxic by-products.
研究领域:
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2015
·Vol. 31
·期 5
·787-791
·
IF 0.875
Tang Cen,Jin Yanxia,Wang Xiaoxia,Hu Gengshen,Xie Guanqun,Li Xiaonian,Luo Mengfei
The manufacture of 1,1-dichloroethylene(1,1-DCE) usually employs liquid phase method to perform the dehydrochlorination of 1,1,2-trichloroethane(TCE), where large amounts of high-concentration salty wastewater is produced inevitably. It has been a long-term goal to achieve the gas phase synthesis of 1,1-DCE via supported catalysts. In this work, the gas-phase synthesis of 1,1-DCE from TCE was studied in the presence of pentaethylenehexamine( PEHA) supported on silica. High and stable selectivity to 1,1-DCE(up to 98%) was obtained, which could be ascribed to the relatively strong basicity of PEHA according to a proposed E2 mechanism. The formation of PEHA chloride from the HCl generated in situ was detected and was considered to be the main reason for the deactivation of PEHA catalyst.
研究领域:
化学工程
·
催化化学
✓ 已验证
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2017
·
IF 5.651
Chenglun Tang,Junqiang Shan,Yanjun Chen,Lingxia Zhong,Tao Shen,Chenjie Zhu,Hanjie Ying
A novel and efficient organic amine and organosolv synergetic pretreatment method was developed to overcome the recalcitrance of lignocellulose to produce fermentable sugars and high-quality salt-free lignin. After optimization of the process parameters, a delignification of 81.7% and total sugar yield of 83.2% (87.1% glucose, 75.4% xylose) could be obtained using n -propylamine (10 mmol/g, biomass) as a catalyst and aqueous ethanol (60%, v/v) as a solvent. The susceptibility of the substrates to enzymatic digestibility was explained by their physical and chemical characteristics. The physical structure of extracted lignin showed higher β -aryl ether bonds content and functionalities, offering the potential for further downstream upgrading. The role of organic amine catalyst and a synergistic mechanism is proposed for the present system.
研究领域:
生物能源
·
植物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
International Journal of Polymer Science
·
2019
·
IF 1.892
Weiping Du,Guiming Zhang,Song Wang,Lianjiang Tan,Huifang Chen
An optical polythiourethane based on m-xylylene diisocyanate (XDI) and 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol (BES) has been studied. Triethylamine was adopted as a catalyst, and the solid-state isothermal cure reaction was carried out using FTIR spectroscopy, in the temperature range of 75°C-105°C. The -NCO absorption band of XDI was used to monitor the conversion of diisocyanate into polythiourethane. The reaction rate enhanced with an increase in the content of the catalyst, and the gel time determined by swelling test was shorter for the system with higher catalyst content. Kinetic parameters were calculated from the infrared spectrum data, and the results showed that the curing reaction of polythiourethane accords with first-order kinetic characteristics. The activation parameters obtained from the evaluation of kinetic data were , , and . The observed negative entropy of activation value supported the formation of a transition state in the cure reaction.
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 CHEMICAL RESEARCH
·
2012
·
IF 0.633
Shuguang Zhou,Mingxia Xu,Siyu Ye,Dashuai Li,Jing Xu,Pei Mao,Jing Xiong
24 Aza-Michael adducts were synthesised in moderate to excellent yields by the addition of 5-substituted uracils to acrylates with ethylamine as a catalyst. Many of the adducts were obtained in almost quantitive yield without column chromatography. The procedure provideded an efficient approach to the synthesis of N-1 uracil adducts using acrylates as acceptors. The structures of the compounds were determined by 1H NMR, 13C NMR, mass spectra and X-ray crystallography analyses. The uracil unit is present in DNA and related natural products and has a broad spectrum of biological activity.
研究领域:
有机化学
·
药物化学
·
生物化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）