RESEARCH ON CHEMICAL INTERMEDIATES
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2022
·Vol. 48
·期 10
·4105-4118
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IF 3.134
Tang Wanjun,Liu Yunyi,Ding Shuang,Zhao Dongmei,Li Tingcheng,Xie Guangyong
MoV 2 O 8 micro-cuboids were environment-friendly prepared via a facile one-step solvothermal route followed by thermal treatment with vanadium pentoxide and ammonium molybdate as raw materials without using harmful solvents or surfactants. Characterization by XRD, FTIR, XPS, SEM and TEM showed that MoV 2 O 8 formed a layered structure by the stacking of nanosheets and assumed a micro-cuboid shape with a thickness of 150∓30 nm, a width of 350∓110 nm and a length of 680∓18 nm. For the first time, the catalytic properties of MoV 2 O 8 micro-cuboids were investigated for the gas-phase ammoxidation of p -chlorotoluene (PCT) to p -chlorobenzonitrile (PCBN). The as-prepared catalyst exhibited high activity and selectivity in the ammoxidation of PCT to PCBN, with a near 100% conversion and 83.6% yield.
Graphical abstract
研究领域:
材料化学
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催化化学
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纳米材料
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绿色合成
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有机反应工程
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DOI
高影响因子
Molecular Catalysis
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2022
·
IF 5.089
Dongting Wu,Ye Lv,Wei Li,Yan Fu,Jinli Zhang
It is highly challenging to develop efficient catalysts for selective oxidation of p-chlorotoluene (PCT) into p-chlorobenzaldehyde (PCB) as PCB easily undergoes over-oxidation. Herein, a new electrochemical strategy was developed for selective oxidation of PCT with high selectivity toward PCB. A self-standing molybdenum phosphide (MoP) anode was directly synthesized on carbon cloth with the assistance of polyvinyl pyrrolidone. The as-synthesized MoP anode with 3D network structure, exhibits the selectivity of 91.4% toward PCB at the conversion of 75.6% in acetonitrile solution containing 0.1 M Bu 4 NClO 4 . During electrochemical oxidation, molecular oxygen-induced transformation of MoP into MoO 2 initiates the activation of PCT into ClC 6 H 5 CH 2 + . The ClC 6 H 5 CH 2 + reacts with molecular O 2 over electrode surface, producing the product of PCB. This work offers a promising strategy to achieve selective oxidation of C H bond based on electrochemical environment.
研究领域:
电化学
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材料科学
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催化
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环境化学
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DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2023
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IF 9.9
Lei Yuan,Cai Xu,Shaoyong Zhang,Mincheng Yu,Xiaozhong Wang,Yingqi Chen,Liyan Dai
The selective C H bond oxidation of aromatic hydrocarbon is an interesting but challenging task, it is desirable to develop efficient heterogeneous non-noble metal catalyst for this reaction. Herein, two kinds of spinel (FeCoNiCrMn) 3 O 4 high entropy oxides were fabricated via two different methods (i.e., c-FeCoNiCrMn, prepared by a co-precipitation method, and m-FeCoNiCrMn, prepared by physically mixing method). Different from traditional environmentally-unfriendly Co/Mn/Br system, the prepared catalysts were employed for the selective C H bond oxidation of p-chlorotoluene to p-chlorobenzaldehyde in a green approach. Compared to m-FeCoNiCrMn, c-FeCoNiCrMn have smaller particles size and larger specific surface area, which were related to the enhanced catalytic activity. More importantly, characterization results disclosed that abundant oxygen vacancies were formed over c-FeCoNiCrMn. Such a result facilitated the adsorption of p-chlorotoluene on the catalyst surface and promoted the formation of *ClPhCH 2 O intermediate as well as the desired p-chlorobenzaldehyde, as revealed by DFT (Density functional theory) calculations. Besides, scavenger tests and EPR (Electron paramagnetic resonance) results indicated that hydroxyl radical derived from H 2 O 2 homolysis was the main active oxidative species for this reaction. This work revealed the role of oxygen vacancy in spinel high entropy oxide and also demonstrated its promising application for the selective C H bond oxidation in an environmentally-benign approach.
研究领域:
催化
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材料科学
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环境化学
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无机化学
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产品关联
DOI
PubMed
高影响因子
Small
·
2026
·
IF 11.8
Ziqi Dong,Feng Niu,Zeqi Wu,Xiaofan Zhou,Junyan Li,Dilshod Nematov,Saidjafar Murodzoda,Huaizhou Jin,Da Chen
The activation of inert C(sp 3 )-H bonds is the rate-determining step in photocatalytic selective oxidation of toluene, and the easy over-oxidation of target products makes it a great challenge in green organic synthesis. Herein, we report a semi-heterogeneous CeCl x -NHPI complex, which is constructed via the coordination of CeCl 3 and N-Hydroxyphthalimide (NHPI) for the efficient visible-light-driven selective oxidation of toluene to benzaldehyde under ambient conditions. Impressively, the catalyst achieved a maximum benzaldehyde formation rate of up to 2 mmol·g −1 ·h −1 in 5 h, with a benzaldehyde selectivity of 80.6%. Mechanistic studies show that the chlorine radicals (Cl·) generated from the coordinated Ce─Cl bond via the ligand-to-metal charge transfer (LMCT) process, and the phthalimide-N-oxyl (PINO) radicals formed from NHPI via single-electron transfer jointly promote the efficient activation of the inert C(sp 3 )-H bond in toluene. In addition, the CeCl x -NHPI complex exhibits good recyclability and broad substrate tolerance for the selective oxidation of various toluene derivatives. This work provides a novel strategy for the design of efficient rare earth-based semi-heterogeneous photocatalysts for the activation of C(sp 3 )-H bonds.
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2025
·
IF 4
Jinhua Xu,Minghui Tang,Jinyu Zhang,Wenmin Zhang,Shiye Xie,Lan Zhang
This study reports the synthesis and application of a flower-like chiral metal-organic framework (CMOF) based on copper ions and tryptophan (Cu(Trp)-CMOF). The Cu(Trp)-CMOF was successfully synthesized at room temperature through a facile method with hexadecyl trimethyl ammonium bromide (CTAB) as a structure-directing agent. The material exhibits a flower-like morphology with hierarchical porosity and well-defined crystallinity in the monoclinic P2 1 /c space group. Comprehensive characterization revealed that different optical configurations ((R)-type, (S)-type, and (RS)-type) could be selectively obtained by controlling the chirality of tryptophan ligands. The synthesized CMOFs demonstrated excellent performance in two key applications: colorimetric recognition of amino acid enantiomers and separation of volatile organic compounds (VOCs). When used as a chromatographic stationary phase, the CMOF significantly enhanced the separation of challenging structural isomers, particularly improving the resolution (R S ) of xylene isomers (R S from 1.03 to 2.62) and ethyltoluene isomers (R S from 4.83 to 9.23) compared to conventional columns. This work provides new insights into the design and application of CMOFs for chiral separation and recognition.
研究领域:
材料科学
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化学
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产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2024
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IF 3.7
Zeqi Wu,Feng Niu,Wenhao Yao,Siyuan Gao,Da Chen,Yuexiang Huang
The activation of an inert C(sp3)–H bond in selective oxidation of hydrocarbons under mild conditions is a critical and challenging process. Herein, we report a stable chlorine-coordinated metal–organic framework (MOF) photocatalyst, MIL-101(Fe), for efficient visible-light-driven photocatalytic selective oxidation of toluene to benzaldehyde in air under ambient conditions. Encouragingly, a benzaldehyde formation yield of 3.11 mmol·g–1·h–1 with a selectivity of 92.1% is achieved in 5 h, which is superior to most of the reported works. Based on the experimental results and characterizations, the high catalytic performance is mainly due to the promoted rate-limiting step of C(sp3)–H bond activation by a chlorine radical (Cl·) from the coordinated −Cl in the MIL-101(Fe) structure. In addition, the present photocatalyst possesses good substrate tolerance for photocatalytic selective oxidation of various toluene derivatives under optimized conditions.
研究领域:
化学
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材料科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
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2024
·
IF 4.9
Yang Liu,Jian Li,Jiawei Liu,Changwei Tang,Quan Bai
Metal-organic frameworks (MOFs) are promising packing materials in liquid chromatography, but their micropore character extremely prevents the separation performance. Herein, we proposed an acidic etching strategy to fabricate a hierarchically porous University of Oslo-66 (HP-UiO-66) coated silica shell-core composite by using phosphoric acid as an etchant. The prepared composite, namely HP-UiO-66@silica-PA, was characterized by SEM, TEM, FT-IR, and N 2 -adsorption–desorption isotherms, demonstrating the generation of mesopores in HP-UiO-66 shell with pore width ranging in 4–5 nm. The chromatographic performance of HP-UiO-66@silica-PA-1 (etched by 1 mL phosphoric acid for 2 h) as HPLC stationary phase was evaluated in reversed-phase mode, and the separations of three groups of small solutes were studied and compared with the microporous UiO-66@silica (MP-UiO-66@silica) column. The results proved the obviously improved performances with narrower peak width, better resolution, and higher symmetry were achieved by the HP-UiO-66@silica-PA-1 column. The faster diffusion and mass transfer kinetics in the HP-UiO-66 shell signally reduce the plate height and improve the column efficiency. Specifically, the plate number of o -xylene was 18,442 plates m −1 , which was about 18.5 times higher than that on the MP-UiO-66@silica column (993 plates m −1 ). Furthermore, good repeatability and reproducibility with RSDs of both retention time and peak area less than 0.5 % confirmed the high stability and outstanding reliability of the HP-UiO-66@silica-PA-1 column. This study demonstrates that the phosphoric acid etching strategy is simple, mild, and controllable to fabricate hierarchically porous MOFs-based stationary phase for enhancing the HPLC separation performance.
研究领域:
分析化学
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材料科学
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色谱
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
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2024
·
IF 4.1
Shandi Zhong,Cai Xu,Quanfu Long,Hang Zhou,Jianhai Yang,Jia Guo,Xiaozhong Wang,Liyan Dai
Using O 2 as an oxidant, developing a non-noble metal catalyst for the selective catalytic C–H bond oxidation of p-chlorotoluene is desirable and challenging. In this work, a series of Co, Cr co-doped OMS-2 (Octahedral Molecular Sieve-2) catalysts were prepared by a conventional refluxing method. It was found that the incorporation of Co and Cr improved the catalytic activity for the selective oxidation of p-chlorotoluene to p-chlorobenzaldehyde. Among these catalysts, CoCr/OMS-2 (Co: Cr = 1: 1, mass ratio), the best catalyst, shows that the conversion and the selectivity of p-chlorobenzaldehyde is 94.8 % and 94.3 %, respectively. The enhanced catalytic activity was due to the larger specific surface area and even dispersion of active components. The characterization results also disclosed that the co-doping of Co and Cr increased the oxygen vacancy and enhanced the ability to activate the surface lattice oxygen. Additionally, density functional theory calculations demonstrated that co-doping of Co and Cr promoted the adsorption of p-chlorotoluene and O 2 , and decreased the energy barrier of rate-determining step (the conversion of p-chlorobenzyl alcohol to p-chlorobenzaldehyde). Besides, when H 2 O was added to the reaction system as the second solvent, the activation and dissociation of O 2 , and the formation of p-chlorobenzaldehyde were facilitated, in agreement with the experimental results. This work demonstrated the promotional effect of Co, Cr co-doped into OMS-2 catalyst and the role of H 2 O for the selective oxidation of p-chlorotoluene.
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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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2025
·
IF 9
Hong-Mei Fu,Xi-Peng Zhang,Shi-Chao Qi,Ding-Hua Liu
The p -chlorotoluene (PCT) and m -chlorotoluene (MCT) are indispensable chemical intermediates in pharmaceuticals, agrochemicals, and material synthesis. However, the similar physical and chemical properties of the PCT and MCT make their efficient separation a severe challenge in the current chemical separation field. In this study, a metal-organic framework named Mn-dhbq (dhbq = 2,5-dihydroxy-1,4-benzoquinone) is employed to achieve highly efficient separation of PCT/MCT in a solvent system with 1,3,5-trimethylbenzene. The Mn-dhbq exhibits the adsorption capacity of 208 mg/g for PCT and 72 mg/g for MCT at 25 °C, with initial concentration of 20 % for both PCT and MCT. Notably, the dual-site Langmuir-Freundlich selectivity is 38 with the concentration of 1 % for PCT and MCT. Density functional theory (DFT) calculations reveal differences in the amount of charge transfer and interaction sites between the framework and adsorbate, and these factors collectively contribute to the selective separation of PCT and MCT by Mn-dhbq.
研究领域:
化学工程
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分离科学
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材料化学
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金属有机框架
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吸附技术
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产品关联
DOI
高影响因子
TALANTA
·
2020
·
IF 5.339
Xue Li,Yuan-Yuan Cui,Cheng-Xiong Yang
Microporous organic networks (MONs) have shown great promise in separation science recently. Exploring novel, simple and convenient strategy to fabricate MONs coated capillary columns for gas chromatography (GC) still remains challenging but desirable for the development of MONs in chromatographic separation. To extend the potential application of MONs in separation science and to further develop novel method for the fabrication of MONs-based capillary columns, here we demonstrate a novel covalent coupling strategy to fabricate uniform MONs bonded capillary columns for GC separation of position isomers and hydrocarbons. The bare capillary column was firstly modified with (3-bromopropyl)trimethoxysilane to provide bromine sites for coupling with alkynyl monomers . The amino- and hydroxyl-functionalized MONs (MON-NH 2 and MON-OH) were then directly grown onto the inner wall of the brominated capillary columns via the covalent coupling between bromine and alkynyl groups. The uniform MON-NH 2 and MON-OH bonded capillary columns were obtained and showed good resolution for GC separation of dichlorobenzene , chlorotoluene, bromotoluene, and propylbenzene position isomers and many other hydrocarbons including linear alkanes, alkylbenzenes , pinene isomers, cyclohexane and benzene, ketones and aldehydes. The MONs bonded capillary columns also owned good lifetime and precision for dichlorobenzene isomers with the relative standard deviations (RSDs) of 0.2–0.3%, 1.2–2.1%, and 1.7–2.5% for retention time, peak height and peak area, respectively. In addition, the fabricated MON-NH 2 and MON-OH bonded capillary columns offered better resolution than commercial InertCap-1, InertCap-5, InertCap-1701 and InertCap-WAX capillary columns for the separation of chlorotoluene and bromotoluene position isomers. These results revealed the feasibility of covalent coupling strategy to fabricate MONs-based stationary phases in GC, highlighting the potential of MONs in separation science.
研究领域:
分析化学
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分离科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2021
·
IF 3.764
Jie Yang,Liyuan Huai,Jiang Gan,Hualei Hu,Shenghu Zhou,Jian Zhang
The 5,5′(oxy-bis(methylene))bis-2-furfural (OBMF) formation from the 5-hydroxymethylfurfural (HMF) self-etherification over zeolites is an important reaction for the synthesis of value-added chemicals from biomass resources. However, there is still a lack of knowledge about the reaction mechanism and the roles of different acid sites that impedes the exploitation of zeolite catalysts for efficient OBMF production. In the present study, the ZSM-5 (HPZ) catalysts of four hierarchically micromesopores were successfully synthesized in different Si/Al ratios by adjusting the amount of Al in the solvent evaporation with the assistance of a dry gel conversion method. The kinetics of OBMF formation from HMF self-etherification was investigated. The apparent activation energy and the conversion reaction order were calculated to be 104.6 kJ/mol and 0.65, respectively. The intrinsic activity comparison of four catalysts and density functional theory (DFT) calculations showed that HMF adsorption and etherification benefit from Brønsted-acid sites. Besides, the DFT results suggested that the etherification proceeds via a concerted step, instead of the sequential pathways, thus leading to the high selectivity of OBMF on hierarchically micromesoporous ZSM-5 (HPZ) catalysts.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2015
·Vol. 38
·期 16
·2880-2886
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IF 2.737
Xi Zhang,Xiaohuan Zang,Guijiang Zhang,Chun Wang,Zhi Wang
A mesoporous carbon was fabricated using MCM-41 as a template and sucrose as a carbon source. The carbon material was coated on stainless-steel wires by using the sol–gel technique. The prepared solid-phase microextraction fiber was used for the extraction of five volatile aromatic compounds (chlorobenzene, ethylbenzene, o -xylene, bromobenzene, and 4-chlorotoluene) from tea beverage samples (red tea and green tea) prior to gas chromatography with mass spectrometric detection. The main experimental parameters affecting the extraction of the volatile aromatic compounds by the fiber, including the extraction time, sample volume, extraction temperature, salt addition, and desorption conditions, were investigated. The linearity was observed in the range from 0.1 to 10.0 μg/L with the correlation coefficients ( r ) ranging from 0.9923 to 0.9982 and the limits of detection were less than 10.0 ng/L. The recoveries of the volatile aromatic compounds by the method from tea beverage samples at spiking levels of 1.0 and 10.0 μg/L ranged from 73.1 to 99.1%.
研究领域:
分析化学
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食品科学
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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）