Molecular Catalysis
·
2023
·
IF 4.6
Xuan Gao,Zhihui Li,Dongsheng Zhang,Baoquan Zhang,Yanji Wang
Efficient and safe conversion of 5-hydroxymethylfurfural (HMF) to 5-hydroxymethyl-2-furancarbonitrile (HMFC) with hydroxylamine zinc chloride salt (ZnCl 2 ·2NH 2 OH) obtained from a novel method was developed. Without a catalyst, free NH 2 OH could react with HMF to produce HMFC with a yield of 41% at 55 °C. ZnCl 2 was an appropriate catalyst that increased HMFC yield to 64%. However, the reaction has a potential explosion safety hazard and a low effective utilization rate of NH 2 OH due to the easy decomposition property of free NH 2 OH. To address these issues, ZnCl 2 ·2NH 2 OH was prepared to serve as a hydroxylamine stabilizer, catalyst, and nitrogen source in the synthesis of HMFC. Therefore, NH 2 OH could be slowly released to participate in the reaction, slowing the invalid decomposition and increasing the utilization rate of elemental N. Under optimal conditions of n(HMF): n(NH 2 OH) = 1:1.5, 100 °C for 20 min with acetonitrile as solvent, the yield of HMFC was 100%. A plausible reaction mechanism for HMFC synthesis was also proposed.
研究领域:
化学
·
有机化学
·
催化
·
安全工程
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DOI
高影响因子
Catalysts
·
2022
·Vol. 12
·期 7
·694
·
IF 4.501
Ji Qi,Ziying An,Xiao Chen,Chuang Li,Yan Du,Xiuhong Zhang,Changhai Liang
The classic acrylonitrile (AN) electrohydrodimerization (EHD) to adiponitrile (ADN) process produces oxygen on the anode side. The oxygen evolution reaction (OER) is energy consuming, and O2is of low value and has security issues while directly contacting with organic molecules. Herein, by replacing OER with 5-hydroxymethylfurfural oxidation reaction (HMFOR), we report paired electrolysis of AN and HMF for simultaneous generation of ADN and 2,5-furandicarboxylic acid (FDCA). On the anode side, the electrodeposited amorphous NiMoP film-covered nickel foam efficiently boosted HMFOR activity by enlarging the electrochemically active surface area (ECSA) via in situ selective removal of Mo and P on the surface. On the cathode side, addition of dimethylformamide (DMF) as a cosolvent enhanced the reaction efficiency of ANEHD by forming a single-phase electrolyte that offers better interaction between AN and the electrode. The ANEHD–HMFOR paired system shows excellent generation rates of FDCA (0.018 gFDCA·h−1·cm−2) and ADN (0.017 gADN·h−1·cm−2) at a high cell current (160 mA). An amount of 1 kWh of electricity can produce 2.91 mol of ADN and 0.53 mol of FDCA with 107.1% Faraday efficiency.Keywords:paired electrolysis;5-hydroxymethylfurfural oxidation;acrylonitrile electrohydrodimerization;adiponitrile;2,5-furandicarboxylic acid;dimethylformamide cosolvent
研究领域:
化学工程
·
电化学
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DOI
高影响因子
Catalysis Science & Technology
·
2019
·Vol. 9
·期 6
·1504-1510
·
IF 5.726
Shanshan Yu,Peiyuan Yao,Jinlong Li,Jinhui Feng,Qiaqing Wu,Dunming Zhu
Nitrilase-catalysed desymmetrization of 3-substituted glutaronitriles to optically active 3-substituted 4-cyanobutanoic acid offers an attractive approach to access chiral β-substituted γ-amino acids, an important moiety in pharmaceuticals. In this study, we employed enzyme-substrate docking and alanine scanning to determine the key amino acid residues which have a positive effect on the activity and stereoselectivity of a nitrilase from Synechocystis sp. PCC6803 (SsNIT). Then, site-saturation mutagenesis and combinatorial mutagenesis of the positive amino acid residues (H141, P194, M197, I201 and F202) were performed, and a double mutant (P194A/F202V) and a triple mutant (P194A/I201A/F202V) with high activity and stereoselectivity were identified for desymmetrization of 3-substituted glutaronitriles to afford (S)-3-substituted-4-cyanobutanoic acids with a high space–time productivity of up to 488 g L−1 d−1. Molecular calculation suggests that the enzymatic activity improvement may be due to the enlargement of the substrate binding cavity. It is interesting that the stereoselectivity is enhanced simultaneously.
研究领域:
生物催化
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酶工程
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化学生物合成
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DOI
高影响因子
Polymers
·
2021
·Vol. 13
·期 23
·4096
·
IF 4.329
Lin Wang,Yanqiang Ni,Xin Qi,Liqun Zhang,Dongmei Yue
Hydrogenated Nitrile Rubber (HNBR) is widely used in aerospace, petroleum exploration and other fields because of its excellent performances. However, there remains a challenge of balancing the oil resistance and the low temperature resistance for HNBR. In this work, a series of grafted carboxyl nitrile rubber (XNBR) was prepared by the esterification reaction between active functional groups (–COOH) of XNBR and alkanols of different molecular chain lengths (C8H17OH, C12H25OH, C16H33OH, C18H37OH) or Methoxypolyethylene glycols (MPEG) of different molecular weights (Mn = 350, 750, 1000). The structure and low temperature resistance of as-obtained grafted polymers were characterized by Fourier Transform Infrared (FTIR),1H-NMR and Differential scanning calorimetry (DSC). It was found that the glass transition temperatures (Tg) of grafted XNBR were significantly decreased. MPEG grafted polymers with better low temperature resistance were then selected for hydrogenation. As-prepared hydrogenated XNBR grafted with MPEG-1000 (HXNBR-g-1000) showed the lowest Tgof −29.8 °C and the best low temperature resistance. This work provides a novel and simple preparation method for low temperature resistant HNBR, which might be used potentially in extremely cold environments.Keywords:hydrogenated nitrile rubber (HNBR);grafting;low temperature resistance
研究领域:
材料科学
·
高分子化学
·
航空航天工程
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DOI
PubMed
高影响因子
ACS Omega
·
2020
·
IF 2.87
Li Wang,Shengxian Liu,Wenjing Du,Tongyi Dou,Changhai Liang
5-Cyanovaleramide (5-CVAM) is an important intermediate of a herbicide and chemical raw material. Herein, we found a novel nitrile hydratase from the strain Rhodococcus erythropolis CCM2595, exhibiting high regioselectivity with higher substrate specificity toward dinitriles than mononitriles. In the past, the strain was shown to degrade only phenol, hydroxybenzoate, p-chlorophenol, aniline, and other aromatic compounds. In our study, 20 mM adiponitrile was completely consumed within 10 min with 95% selectivity to 5-CVAM and 5% selectivity to adipamide. In addition to its high regioselectivity, our recombinant Escherichia coli showed a higher substrate tolerance of up to 200 mM adiponitrile even after 3 h when compared with two reported strains with their cyano-tolerance concentrations of up to 100 mM, which is considered to be the highest cyano-tolerance. Such a robust biocatalyst is a desirable attribute of a biocatalyst intended for use in commercial applications of 5-CVAM.
研究领域:
生物催化
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生物化学
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化学工程
·
酶技术
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产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Guang-Rong Ding,Yao-Feng Wang,Guo-Yi Duan,You-Qian Fan,Bao-Hua Xu
In this study, a tungstated zirconia (WOx/ZrO2) catalyst was developed for the continuous synthesis of adiponitrile (ADN) by gas-phase nitrilation of dimethyl adipate (DMA) with NH3. The highest TOFADN could be reached on WOx/ZrO2 bearing ∼1D WOx species (highly dispersed and discontinuous status) at the surface, which, however, delivered the poorest selectivity toward nitrilation (SADN+MCP). In comparison, both efficient and selective transformation of DMA to ADN was achieved by fabricating WOx/ZrO2 with continuously distributed oligomeric WOx species (∼2D) at the surface, either by varying the dosage of the W-reagent in the preparation of WOx(m)/ZrO2 or by doping a proper amount of the Mn element into WOx(5.0)/ZrO2, bearing WO3 NPs. Furthermore, the in situ diffuse reflectance infrared Fourier transform spectroscopy investigations of both independent and competitive adsorptions of ester functionality and NH3 over W–O–Zr, W–O–W, and Zr–O–Zr boundaries at the surface clarified the synergistic effect of these species in the activation of DMA/NH3 and thereby nitrilation.
研究领域:
催化
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化学工程
·
表面科学
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产品关联
DOI
PubMed
高影响因子
HIGH PERFORMANCE POLYMERS
·
2021
·
IF 2.161
Shajie Luo,Fajian Ren,Jiangang Dai,Yan Chen,Zhongzhu Yang
Two kinds of novel poly(arylene ether nitrile)s (CPDP-DCBN and CHDP-DCBN) containing pendant aliphtatic ring were synthesized by 4,4′-cyclopentane-1,1′-diyldiphenol (CPDP) or 4,4′-cyclohexane-1,1′-diyldiphenol (CHDP) and 2,6-dichlorobenzonitrile (DCBN) in this work. The inherent viscosities of poly(arylene ether nitrile)s (PENs) were in the range of 0.701–0.806 dL g−1. The polymers showed high glass transition temperatures (Tg) of 185.4–196.4°C and weight-loss temperatures (T5%) of 447.8–454.3°C. The obtained CPDP-DCBN and CHDP-DCBN could be hot pressed into the films, which showed the tensile strengths of 82.6 MPa and 86.8 MPa, respectively. And the storage modulus of CPDP-DCBN and CHDP-DCBN were about 1.0 GPa and 1.5 GPa at 150°C, respectively. Additionally, the PENs could be dissolved in many solutions at room temperature, such as NMP and concentrated H2SO4, indicating that they had good solubility; they can be processed by the solution method. Meanwhile, the optical transmittance of CPDP-DCBN was 78.1% at 450 nm; it has potential to be applied to the heat-resistant optical film.
研究领域:
高分子化学
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材料科学
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产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2015
·Vol. 17
·期 7
·3992-3999
·
IF 8.02
Shujing Zhu,Xiaoqiang Ma,Erzheng Su,Dongzhi Wei
From an environmental perspective, utilizing nonconventional solvents (i.e. green solvents) with low ecological footprints is a highly beneficial alternative to using conventional organic solvents to form a reaction system. The nitrile hydratase (NHase, EC 4.2.1.84) catalyzed hydration of 2-amino-2,3-dimethylbutyronitrile (ADBN) to 2-amino-2,3-dimethylbutyramide (ADBA) in various green solvent–aqueous reaction systems was investigated in this study. After systematically optimizing the reaction conditions, the HFE-7100/H2O (v/v, 10%) biphasic system was ultimately identified as a promising reaction system for reducing product inhibition, avoiding substrate hydrolysis, and facilitating product separation and solvent recovery. The average ADBA yield of an entire batch reaction was 97.3%, which is obviously higher than those obtained with previously reported chemical or enzymatic methods. This is the first attempt to apply a fluorous solvent–aqueous biphasic system to a biocatalytic process, and the results suggest that the fluorous solvent employed in the biphasic system satisfies the requirements for green chemistry.
研究领域:
生物化学
·
环境科学
·
绿色化学
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DOI
高影响因子
ADVANCES IN POLYMER TECHNOLOGY
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2021
·
IF 2.389
Yuanying Zhang,Xuechun Zhang,Yongbin Cao,Jiachun Feng,Wuli Yang
Herein, acrylonitrile-styrene-acrylate copolymer (ASA) particles with different microstructure were synthesized by emulsion polymerization and then used for toughening poly(styrene-co-acrylonitrile) (SAN) resin. The structure of ASA particles was confirmed by FTIR. TEM results demonstrated that the particles with different morphologies of multilobe shape, complete core-shell and dumbbell shape were obtained depending on the cross-linker amount. It was found that the toughening efficiency reached the highest when the ASA particles had complete core-shell structure and the shell composition was close to that of the SAN matrix. It was ascribed to the fact that the complete shell layer and similar shell composition provided sufficient interfacial adhesion and transferred stress to induce larger matrix deformation, so that the notched impact strength increased accordingly. Moreover, the notched impact strength of SAN/ASA blend was improved without significantly sacrificing tensile strength when adding 30 wt% ASA particles with the size of around 400 nm. SEM results of the impact-fractured surfaces revealed that irregular fluctuation and numerous microvoids occurred. It was deduced that the toughening mechanism was attributed to the crazings and cavitation of particles. Therefore, this study paved a way of toughening the resin by adjusting the microstructure of the particles including morphology, composition, and size.
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2023
·
IF 11.4
Yingying Zhou,Jia-jia Jiao,Huang Huang,Yong Dong Liu,Rugang Zhong,Xin Yang
Dichloroacetonitrile (DCAN) as one of the potentially prioritized regulated DBPs has drawn great attention; however, understanding its formation, especially the C–C bond cleavage mechanisms, is limited. In this study, DCAN formation mechanisms from long-chain primary amines, amino acids, and dipeptides during chlorination were investigated by a combined computational and experimental approach. The results indicate that nitriles initially generate for all of the above precursors, then they undergo β-C-hydroxylation or/and α-C-chlorination processes, and finally, DCAN is produced through the Cα–Cβ bond cleavage. For the first time, the underlying mechanism of the C–C bond cleavage was unraveled to be electron transfer from the O– anion into its attached C atom in the chlorinated nitriles, leading to the strongly polarized Cα–Cβ bond heterocleavage and DCAN– formation. Moreover, DCAN molar yields of precursors studied in the present work were found to be determined by their groups at the γ-site of the amino group, where the carbonyl group including −CO2–, −COR, and −CONHR, the aromatic group, and the −OH group can all dramatically facilitate DCAN formation by skipping over or promoting the time-consuming β-C-hydroxylation process and featuring relatively lower activation free energies in the C–C bond cleavage. Importantly, 4-amino-2-hydroxybutyric acid was revealed to possess the highest DCAN yield among all the known aliphatic long-chain precursors to date during chlorination. Additionally, enonitriles, (chloro-)isocyanates, and nitriles can be generated during DCAN formation and should be of concern due to their high toxicities.
研究领域:
环境化学
·
水处理
·
毒理学
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产品关联
DOI
PubMed
高影响因子
ECS Journal of Solid State Science and Technology
·
2015
·Vol. 5
·期 2
·P21
·
IF 1.558
Bin Hu,Wen Luo,Lin Jin,Zengchen Liu,Mengnan Wang,Liuyang Zhou,Chunyang Li
Two novel carbazole-3, 4-ethoxylenedioxythiophene (EDOT) derivatives containing acceptor groups such as benzonitrile and phthalonitrile were synthesized and characterized. Both the monomers could be electrochemically polymerized and form stable electroactive polymer films. Spectroelectrochemical technique were performed to investigate the electrochemical and optical changes of the resulting polymer films, multi-electrochromic properties upon different applied potentials suggested the effect of the benzonitrile and phthalonitrile units and their potential applications in electrochromic device. Furthermore, scanning electron micrographs (SEM) were used to study the microstructure morphology of polymer films.
研究领域:
材料科学
·
电化学
·
高分子化学
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产品关联
DOI
高影响因子
Materials Chemistry Frontiers
·
2022
·Vol. 6
·期 4
·430-439
·
IF 8.683
Ling Liu,Yinghui Cai,Zhikun Zhao,Chengwei Ma,Chunli Li,Daobin Mu
Hybrid solid electrolytes have been widely studied due to their favorable flexibility, high mechanical strength, and good interfacial contact with electrodes. However, the relatively low ionic conductivity of hybrid solid electrolytes and poor interfacial compatibility restrict their practical application. In this study, a succinonitrile electrolyte (SNE) infiltrated silica aerogel (SAG)/polyacrylonitrile (PAN) hybrid solid electrolyte (SSP) was fabricated. As-prepared SSP exhibits high ionic conductivity of 7.45 × 10−4 S cm−1 (30 °C) and a high tLi+ transference number of 0.70. This is attributed to the synergistic effect of the porous skeleton of SAG and the high conductivity of SNE providing multiple Li+ transport channels. In-depth analysis demonstrates that SSP possesses fast Li+ mobility and plenty of freely mobile Li+ ions and it exhibits favorable interfacial compatibility with the anode and cathode. As a result, a symmetrical Li/SSP/Li cell can undergo long-term cycling for 700 h at 0.1 mA cm−2. Moreover, an NCM811/SSP/Li cell could exhibit a high discharge capacity of 200.5 mA h g−1 at 0.1 C and excellent rate performance with a capacity of 80.8 mA h g−1 at 5 C. Remarkably, the NCM811/SSP/Li cell demonstrates outstanding cycling stability with 73.2% capacity retention after 200 cycles at 1 C.
研究领域:
材料科学
·
电化学
·
能源存储
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DOI
高影响因子
危险品化学品经营许可证（带存储）