CHEMICAL ENGINEERING JOURNAL
·
2026
·
IF 12.5
Xiaoyan Zheng,Hanwen Yan,Junyang Liu,Jie Li,Junping Zhang,Songsong Chen,Hongnan Chen,Gang Wang,Chunshan Li
Two types of N -methylation and N -formylation during MAL synthesis was revealed. • Comprehensive thermodynamic and kinetic studies were systematically conducted. • The formate species was identified as the key intermediates for these reactions. • Reaction networks for N -methylation and N -formylation were proposed. Synthesis of methacrolein (MAL) from propionaldehyde and formaldehyde (FA) via mild Mannich reaction catalyzed by sec-amine is a crucial step for methyl methacrylate (MMA) production. However, the undesired N -methylation and N -formylation of catalytically active sec -amine centers by FA leads to catalyst consumption. In this work, comprehensive thermodynamic and kinetic investigations were conducted for these two types of crucial side reactions on the basis of reaction networks understanding. It was identified by in situ ATR FTIR that the generated formic acid/formate species are responsible for the formation of N -methyldiethanolamine and N, N -bis (2-hydroxyethyl) formamide byproducts. Thermodynamic analyses confirmed required parameters and demonstrated that these reactions are both exothermic and product-favored under standard condition, with N -methylation exhibiting much stronger driving force than N -formylation. Kinetic assessments further revealed reaction rate constants, reaction orders and activation energies, with deviation within 5%, and lower reaction barrier of N -formylation than N -methylation. These findings suggest practical strategies for reaction process optimization and catalyst stability improvement.
✓ 已验证
DOI
高影响因子
Materials
·
2025
·Vol. 18
·期 20
·4705
·
IF 3.2
Weijie Hua,Huixin Yuan,Songhua Huang
This research successfully synthesized a novel n-n heterojunction Bi2O2CO3/AgVO3nanocomposite photocatalyst via the in situ chemical deposition process. Characterization results strongly confirmed the formation of a tight heterojunction at the Bi2O2CO3/AgVO3interface. The nanocomposite exhibited characteristic XRD peaks and FT-IR vibrational modes of both Bi2O2CO3and AgVO3simultaneously. Electron microscopy images revealed AgVO3nanorods tightly and uniformly loaded onto the surface of Bi2O2CO3nanosheets. Compared to the single-component Bi2O2CO3, the composite photocatalyst exhibited a red shift in its optical absorption edge to the visible region (515 nm) and a decrease in bandgap energy to 2.382 eV. Photoluminescence (PL) spectra demonstrated the lowest fluorescence intensity for the nanocomposite, indicating that the recombination of photogenerated electron–hole pairs was suppressed. After 90 min of visible-light irradiation, the degradation efficiency of Bi2O2CO3/AgVO3toward methylene blue (MB) reached up to 99.55%, with photodegradation rates 2.51 and 2.79 times higher than those of Bi2O2CO3and AgVO3, respectively. Furthermore, the nanocomposite exhibited excellent cycling stability and reusability. MB degradation was gradually enhanced with increasing the photocatalyst dosage and decreasing initial MB concentration. Radical trapping experiments and absorption spectroscopy of the MB solution revealed that reactive species h+and ·O2−could destroy and decompose the chromophore groups of MB molecules effectively. The possible mechanism for enhancing photocatalytic performance was suggested, elucidating the crucial roles of charge carrier transfer and active species generation.
✓ 已验证
DOI
PubMed
高影响因子
Small
·
2022
·Vol. 18
·期 15
·2106581
·
IF 15.153
Zhaolin Gou,Huiqi Qu,Hanfang Liu,Yiru Ma,Lingbo Zong,Bin Li,Congxia Xie,Zhenjiang Li,Wei Li,Lei Wang
2D heterostructures provide a competitive platform to tailor electrical property through control of layer structure and constituents. However, despite the diverse integration of 2D materials and their application flexibility, tailoring synergistic interlayer interactions between 2D materials that form electronically coupled heterostructures remains a grand challenge. Here, the rational design and optimized synthesis of electronically coupled N-doped mesoporous defective carbon and nitrogen modified titanium carbide (Ti 3 C 2 ) in a 2D sandwiched heterostructure, is reported. First, a F127-polydopamine single-micelle-directed interfacial assembly strategy guarantees the construction of two surrounding mesoporous N-doped carbon monolayers assembled on both sides of Ti 3 C 2 nanosheets. Second, the followed ammonia post-treatment successfully introduces N elements into Ti 3 C 2 structure and more defective sites in N-doped mesoporous carbon. Finally, the oxygen reduction reaction (ORR) and theoretical calculation prove the synergistic coupled electronic effect between N-Ti 3 C 2 and defective N-doped carbon active sites in the 2D sandwiched heterostructure. Compared with the control 2D samples (0.87–0.88 V, 4.90–5.15 mA cm −2 ), the coupled 2D heterostructure possesses the best onset potential of 0.90 V and limited density current of 5.50 mA cm −2 . Meanwhile, this catalyst exhibits superior methanol tolerance and cyclic durability. This design philosophy opens up a new thought for tailoring synergistic interlayer interactions between 2D materials.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOLUTION CHEMISTRY
·
2022
·Vol. 51
·期 7
·735-751
·
IF 2
Zhao Zhongqian,Chen Xiumin,Wu Jian,Wang Wenjing,He Bingyang,Yin Qi,Xu Peilin,Liu Li
Density functional theory was used to study the effect of N , N -diethylacetamide (DEAc) in the preparation of ferrous oxalate dihydrate. The calculation results indicated that DEAc molecules can affect the growth of ferrous oxalate dihydrate crystals by hydrogen bonding and van der Waals forces with \({\text{C}}_{2} {\text{O}}_{4}^{2 - }\) or H 2 O in ferrous oxalate dihydrate crystals. DEAc encases ferrous oxalate dihydrate crystals to inhibit crystal growth, and preferentially binds to both sides of \({\text{C}}_{2} {\text{O}}_{4}^{2 - }\) to control the axial growth of ferrous oxalate dihydrate crystals. The experimental program was conducted based on these theoretical calculation results. Rod-shaped particles with a particle size of 100 nm were obtained by adding DEAc during the preparation of ferrous oxalate dehydrate. Therefore, DEAc had a significant effect on the particle size of the ferrous oxalate dihydrate. The theoretical calculations were thus confirmed by the experimental results. And this work explains the growth mechanism of the ferrous oxalate dihydrate.
✓ 已验证
产品关联
DOI
高影响因子
BIOORGANIC CHEMISTRY
·
2022
·
IF 5.307
Han Xu,Ninghua Fu,Jie Zheng,Muhammad Sohail,Xing Zhang
Metal-organic frameworks (MOFs), as advanced enzyme immobilization platforms for improving biocatalysis and protein biophysics, are rarely investigated as solid supports in the enzymatic synthesis of carbohydrate and derivatives, which can be attributed to the complex biochemical reaction mechanisms and the adverse interactions between the high polarity of substrate sugars, glycoenzymes and traditional MOFs. Here, we introduced divalent metal ion Mn 2+ into MOF to prepare bimetallic MOF microreactor that encapsulated N -acetylhexosamine 1-Kinase (NahK), a critical anomeric kinase involved in the enzymatic synthesis of sugar nucleotide. The introduced Mn ions not only adjusted the microstructure of MOFs, but also participated in the enzymatic catalysis as cofactor, thus facilitated the N -acetylglucosamine/ N -acetylgalactosamine (GlcNAc/GalNAc) phosphorylation. The Mn-doped [email protected] organic material (MOM), integrated with high catalytic activity, high stability, and high recoverability, solved the issues of immobilization related to glucokinase activity. These features significantly improved the operability and reduced the processing cost, assuring industrial application prospects for sugar nucleotides synthesis.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2022
·
IF 3.841
Shuai Zhang,Xiaoyu Fan,Shuhan Jiang,Rentian Guan,Xiaodong Shao,Shuhao Wang,Qiaoli Yue
Trace moisture was firstly measured in methanol, ethanol and n-propanol at room temperature. The N, P-codoped carbon dots (CDs) were prepared by one pot solvothermal method, which displayed solvent-dependent fluorescence. The N, P-codoped CDs exhibited green fluorescence, with the quantum yields (QY) of 27.9%, 37.4%, 26.2% and 2.3% in methanol, ethanol, n-propanol and water, respectively. Based on the hydrogen bond interactions between the protic solvents and the N, P-codoped CDs, with the water content increased, the fluorescence intensity of N, P-codoped CDs gradually decreased in methanol, ethanol and n-propanol. The decrement in the fluorescence intensity is linearly related to the water content within the content range of 2% to 8%, 0.04% to 5% and 0.04% to 1.0%, with a limit of detection of 0.22%, 0.009% and 0.021% in methanol, ethanol and n-propanol, respectively. Therefore, the present system has a prospective value for the application in the determination of trace water in the relevant fields.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2021
·
IF 2.694
Xiaoyu Wang,Jiale Wang,Lijun Ji,Bin Wu,Kui Chen,Yanyang Wu
Wastewater containing DMF (N,N-dimethylformamide) and salt is generated in production of many chemicals and medicines. The composition of phase equilibrium should be known primarily for the recovery of DMF from salt-containing wastewater by solvent extraction. In this study, liquid–liquid equilibrium (LLE) and solubility data of water + DMF + chloroform in the presence of NaCl with various concentrations of 0, 2.5, 5.0, 7.5, 10.0, and 13.3 wt % and Na2SO4 with concentrations of 1.5 and 2.5 wt % were determined at T = 298.2 K and atmospheric pressure. Besides, the salt effect on the LLE data was investigated. Compared with the salt-free system, the salt led to an enhancement in the maximum DMF distribution coefficient by 13.4–102.6% for 2.5–13.3 wt % NaCl and 16.2–31.7% for 1.5–2.5 wt % Na2SO4, respectively. Since the distribution coefficient of water increased concurrently, the separation factor barely changed and the two-phase region expanded outward slightly. At the same salt mass fraction, the order of salting-out effect strength on extraction was Na2SO4 > NaCl, which was in good agreement with the Hofmeister series. The reliability of the experimental values was verified through the Eisen–Joffe equation. The NRTL thermodynamic model was applied to correlate the experimental data with a root-mean-square deviation less than 0.0062. The coherent consistency of the model parameters for the salt-free system was checked by topological analysis based on the Gibbs tangent plane test.
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2021
·
IF 5.909
Tao Li,Lin Dai,Yixin Huang,Siwen Pan,Zijun Pang,Jing Zou
Nowadays, a number of spectrophotometric methods for Cr(VI) determination have been developed. Whereas most of them are sensitive to pH, metallic ions, temperature, etc, which render them out of feasibility and may result in erroneous measurement. Therefore, to overcome these drawbacks, a new spectrophotometric method with rapid detection, high accuracy and strong anti-interference ability was established. This method is based on the oxidative coloration of N,N -diethyl- p -phenylenediamine (DPD) and Cr(VI) to generate pink-colored DPD •+ radicals which showed maximum absorbance at 551 nm. Accordingly, different reaction parameters were optimized, the calibration curves (linear range 0.85–60 µM) were established with a high sensibility of (3.05 ± 0.02) × 10 4 M −1 cm −1 . The LOD and LOQ were determined to be 0.26 µM and 0.85 µM respectively, accompanied with a stoichiometric coefficient of near 1:3 (1:2.78). The DPD method exerted a satisfactory accuracy in natural water samples and a pretty good anti-interference performance towards various common co-existing metallic ions. Moreover, this method was successfully applied in the Cr(VI)-sulfite and Cr(VI)-hydroxylamine systems. Overall, the study highlights the DPD method as a promising approach for the Cr(VI) determination and provides a new perspective for the practices of spectrophotometry .
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2020
·
IF 2.888
Meng-Ling Dai,Zhi-Gao Sun
The isochoric stepwise heating method is used to study the effect of liquid hydrocarbon n -tetradecane and n -tetradecane/ n -heptadecane on the equilibrium dissociation conditions of carbon dioxide hydrate. The addition of n -tetradecane or n -tetradecane/ n -heptadecane reduces carbon dioxide hydrate phase equilibrium pressures . As the temperature increases, the promotion effect of the liquid hydrocarbons is more obvious. The promotion effect of n -tetradecane is stronger than that of the mixture of n -tetradecane and n -heptadecane at higher temperature. The quadruple point of carbon dioxide hydrate with the mixture of n -tetradecane and n -heptadecane ( w = 0.3363) is almost the same as that of carbon dioxide hydrate in pure water.
✓ 已验证
产品关联
DOI
高影响因子
Crystals
·
2020
·Vol. 10
·期 6
·528
·
IF 2.404
Chao Liu,Weiwei Zhang,Gaigai Cai
Two copper coordination compounds bearing an N,N’-dibenzylethylenediamine ligand, namely [Cu3L(CH3COO)6]n(1) and [(CuCl4)∙(C6H5CH2NH2CH2)2] (2) (L=N,N’-dibenzylethylenediamine) were synthesized by the ethanol refluxing method. Powder X-ray diffraction (PXRD), infrared spectra (IR), elemental analyses, and single crystal X-ray diffraction were used to characterize and verify their structures. Structural analyses showed that the asymmetric unit of compound (1), composed of two Cu(II) cations, three acetate anions, and half of the ligand, was bridged by one acetate to obtain an infinite 1D chain structure. The analyses further showed that the asymmetric unit of compound (2), composed of two crystallographically independent [C6H5CH2NH2CH2]+units, four chloride anions, and one central Cu(II) cation is connected into an infinite 2D network structure by the hydrogen bonding interactions. The copper compounds were used to catalyze the decomposition of H2O2,and the results showed that both of the compounds exhibited excellent catalytic activities under optimized conditions.Keywords:N,N’-dibenzylethylenediamine;crystal structure;catalyst;coordination compound
✓ 已验证
产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 12
·1-9
·
IF 5.479
Zhang Cong,Liu Di,Zhang Han,Tan Xingrong,Chen Shihong
A ratiometric electrochemiluminescent (ECL) assay is described for the determination of the calcium(II) regulator calcitonin (CT). The method is making use of (a) graphite-like carbon nitride (g-C 3 N 4 ) as the cathodic luminophore, (b) N-(aminobutyl)-N-(ethylisoluminol) (ABEI) as the anodic luminophore, and (c) peroxodisulfate and dissolved oxygen as coreactants. The luminous potential of g-C 3 N 4 and ABEI can be well distinguished because of their different luminescent properties. Energy transfer between g-C 3 N 4 and ABEI is not observed, and the coreactants peroxodisulate and oxygen do not interfere with each other. Au nanoparticles were functionalized with g-C 3 N 4 and placed on the electrode to serve as a matrix for immobilization of primary antibody (Ab 1 ). In the presence of CT, it will bind to the electrode. Then secondary antibody (Ab 2 ) modified with polyaniline (PANI) and ABEI is incubated onto the electrode. With the increase in the concentration of CT, the blue ECL of g-C 3 N 4 is quenched by PANI, while the blue luminescence of ABEI is enhanced. This enables ratiometric detection of calcitonin by ratioing the internsities at 460 and 475 nm. Response is linear in the 0.1~40 pg·mL −1 CT concentration range, and the limit of detection is 23 fg·mL −1 . The method breaks the limitation of common ECL ratiometric strategy, namely, two luminophores often share the common coreactant.
Schematic representation of an immunoassay where polyaniline (PANI) in a BSA-Ab 2 -ABEI-Au@PANI composite quenches the cathodic signal of a graphitic carbon nitride (Au-g-C 3 N 4 ) modified with gold nanoparticles (Au), while N-(aminobutyl)-N-(ethylisolumino) (ABEI) in the BSA-Ab 2 -ABEI-Au@PANI composit produces an anodic signal that enables quantitation of calcitonin.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers in Chemistry
·
2023
·
IF 5.5
Jia Liu,Su-Hang He,Hugues Lambert,Tung-Chun Lee
Resazurin (Alamar Blue, RZ) is a widely utilized fluorescent probe for biological sensing, whose fluorescent intensity can be modulated by changing its redox states; thereby, electrochemical reactivity of RZ is of significance when designing a sensing assay. Herein, we report novel two-way electrochemical reactivity modulation of RZ using host-guest complexation with rigid molecular containers cucurbit[ n ]uril (CB n , n = 7, 8). The complexation between CB n and RZ is confirmed by 1 H NMR measurements and supported by computational simulation, and the binding constants are determined via UV-vis titration. Notably, the voltametric data highlights that the redox reactivity of RZ can be activated or deactivated upon encapsulation by CB8 or CB7, respectively. This two-way reactivity modulation is hypothesized to be mediated by the difference in cavity volume that favors or hinders the approach of water molecules to the encapsulated reaction center during the reduction process. Despite the similar cavity size to CB, molecular containers such as cyclodextrins (CDs) exhibit considerably weaker modulation effects. Our approach can potentially be applied to other redox processes that involve proton transfer, and open new possibilities in supramolecular electrochemistry.
✓ 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）