JOURNAL OF CATALYSIS
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2017
·
IF 6.844
Huifang Liu,Min Wang,Hongji Li,Nengchao Luo,Shutao Xu,Feng Wang
Catalytic oxidation of C C bond is a key technology to transform petroleum-based as well as sustainable biomass feedstock into more valuable oxygenates. We herein describe a convenient and useful oxidation strategy of converting ketones into carboxylic acids using homogeneous copper catalyst without additives and with O 2 as the terminal oxidant. A wide range of aryl and aliphatic ketones as well as β–O–4 lignin models were selectively oxidized to acids via C C bond cleavage. Mechanism studies by EPR and in situ NMR elucidate the principles of Cu/O 2 reactivity that involves C H bond and O 2 activation via a peroxide species. This provides an important foundation for expanding the scope of useful aerobic oxidation reactions using copper catalysts.
研究领域:
有机化学
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催化化学
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Lei Wang,Xin Zhang,Yonggang Sun,Yulong Ma,Min Xu,Juan Zhang,Yingbo Zhu,Li Zhu,Song Qiao,Jing Ma,Jinpeng Wei,Feng Lin
Environmental H 2 O has a significant effect on the reaction mechanism and process of VOC oxidation, of which the intrinsic mechanism is hardly reported. Herein, a series of PtCu δ -MnO x catalysts with different strong metal-supported interactions were constructed by replacing some Pt species with Cu species. Among them, the PtCu 3 -MnO x catalyst exhibited superior catalytic performance (T 90 = 170 ℃), high water resistance, and long-term stability. Furthermore, in-situ diffuse reflectance infrared Fourier transform spectroscopy ( in-situ DRIFTs) showed that the acetone oxidation followed synergistic cooperation of the Langmuir-Hinshelwood (L-H) and Mars van Krevelen (MvK) mechanism. Acetone oxidation over PtCu 3 -MnO x occurred via the L-H mechanism producing surface acetate and formate species intermediate. Above 100 °C, adsorbed acetone (i.e., acetate and formate species) reacts with MnO x lattice oxygen according to the MvK mechanism to form CO 2 and H 2 O. When water vapor was present, the L-H mechanism was impaired, inhibiting the deep oxidation of acetone. This research provides an in-depth exploration of how water vapor impacts the reaction mechanism of acetone oxidation. It offers valuable insights for creating dependable catalysts suitable for use in various industrial settings.
研究领域:
催化化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2017
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IF 3.648
Ruirui Xie,Hongjun Zang,Hongying Ding,Bing Yan,Bowen Cheng
Efficient molybdenum- and tungsten-based catalysts have been reported for the oxidation of furoin and 5,5′-dihydroxymethyl furoin (DHMF) to furil and 5,5′-bihydroxymethyl furil (BHMF), respectively. The catalytic oxidation reactions were performed using oxygen in air as the accelerator in acetic acid solvent. Under the optimized reaction conditions and by using tetra-hexadecyltrimethyl ammonium octamolybdate ([CTAB] 4 Mo 8 O 26 ) as a catalyst, excellent conversions to furil (~ 100%) and BHMF (~ 94%) were observed in a shorter reaction time compared to the other catalysts. This oxidation reaction has been performed by using acetic acid as a solvent under air for the first time, and the catalysts can be readily recycled with no noticeable loss in their catalytic activity over five consecutive catalytic cycles. In this manner, the catalytic system developed in this work is a greener and more environmentally benign process for the oxidation of furoin and DHMF.
研究领域:
有机化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2014
·Vol. 144
·期 7
·1188-1196
·
IF 2.291
Zhu Lihua,Cao Maohong,Zhou Hua,Zhang Nuowei,Zheng Jinbao,Li Yunhua,Chen Bing H.
Abstract
A series of CaO/Al 2 O 3 base catalysts with different crystal phases is prepared via thermal treatment. The as-prepared base catalysts are tested through Baeyer–Villiger oxidation of cyclohexanone to ε-caprolactone in liquid-phase using a mixture of aqueous hydrogen peroxide and benzonitrile as oxidant. The corresponding results show that the CaO/Al 2 O 3 catalysts with high thermal treatment temperature (e.g. 900 °C) exhibit excellent activity as well as stability. Upon these, the catalysts are characterized by TG–DTG, XRD, N 2 -physisorption, SEM and CO 2 -TPD techniques. The characterization results clearly suggest that such a stable and efficient catalytic performance is beneficial from the formation of calcium aluminate phase, thus overcoming one of base catalyst application barriers, that Ca or CaO species loss (leach) from CaO-based catalysts during reactions. Correspondingly, it can be inferred that the treatment of the catalysts at different temperatures results in the diverse distribution of basic strength. Furthermore, it is also demonstrated that the suitable base strength (medium strength is good for the reaction selected in the work) plays a critically role in the improvement of catalytic performance. Finally, the effects of operation conditions on catalytic activity and product selectivity are also determined and discussed. Graphical Abstract
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ORGANIC & BIOMOLECULAR CHEMISTRY
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2017
·Vol. 15
·期 16
·3427-3434
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IF 3.564
Dan Wang,Kuan Zhang,Luhan Jia,Danting Zhang,Yue Zhang,Yujia Cheng,Chang Lin,Bo Wang
Presented here is the first example of synthesizing an array of primary-, secondary-, and tertiary-α-ketoamides with a non-metal catalyst nBu4NI from methyl ketones and inexpensive readily available amine/ammonium salts; the reactions proceeded smoothly under mild conditions, TBHP was used as an oxidant and the corresponding α-ketoamides were afforded in moderate to excellent yields.
研究领域:
有机化学
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催化化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
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2023
·
IF 3.6
Meiqiong Zheng,Chao Huang,Jian-Zhong Yan,Shu-Li Xie,Shao-Jia Ke,Hai-Dong Xia,Ya-Nan Duan
It is highly desirable to avoid using rare or toxic metals for oxidative reactions in the synthesis of pharmaceuticals and fine chemicals. Hypervalent iodine compounds are environmentally benign alternatives, but their catalytic use has been quite limited. Herein, the protocol for in situ hypoiodite-catalyzed oxidative rearrangement of chalcones is first realized under mild and metal-free conditions, which provided a nontoxic, environmental-benign, and catalytic alternative to the thallium-based protocol. Also, the applicability and effectiveness of this catalytic protocol got well demonstrated via gram-scale synthesis and product derivatization. What is more, control and NMR tracking experiments were performed to figure out the possible catalytic species and intermediates.
研究领域:
有机化学
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药物合成
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环境化学
✓ 已验证
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
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2023
·Vol. 47
·期 23
·11051-11062
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IF 3.3
Chengzhi Hu,Changyan Zhou,Huiping Zhang,Ying Yan
Chemical vapor deposition (CVD) and impregnation (IM) methods were applied in the preparation of novel Fe/LTA (Linde Type A) zeolite membrane/paper-like sintered stainless steel fiber (Fe/LTA/PSSF) catalysts for acetone oxidation. The catalysts were characterized using various techniques, such as actual iron loading (AAS), surface morphology (SEM), phase composition and crystallite size (XRD), specific surface area (BET), valence state (XPS) and reducibility (H2-TPR), to investigate the effects of the calcination process, iron loading, preparation methods and supports on their catalytic activity. The calcined catalysts were more active than the non-calcined catalysts in the catalytic oxidation of acetone due to the different oxidation states of the deposited metal species. The catalysts prepared by CVD with an Fe loading of 2.29% exhibited similar activity to the IM-prepared catalysts with Fe loadings of 4.42% and 9.69%, which may be attributed to the superior dispersion of the active Fe2O3 phases, the smaller size of metal oxide and the increased ability for oxygen storage. Among the IM-prepared catalysts, Fe/LTA/PSSF-IM-2 with an Fe loading of 4.42% exhibited the lowest T90 of 230 °C. Additionally, the catalysts coated on LTA/PSSF showed higher activity and contact efficiency (T90 of 249 °C) compared to those on granular zeolite (T90 of 318 °C).
研究领域:
催化化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
·
2025
·
IF 1.9
Guanwen Chen,Bo Yuan,Ruolin Wang,Min Yang,Zhanke Wang,Guangxu Zhang
As an important monomer material for synthesizing polycaprolactone, ε-caprolactone (ε-CL), is currently produced through the Baeyer–Villiger oxidation of cyclohexanone. As a green and promising process to produce ε-CL, oxidizing cyclohexanone with air in the presence of sacrificial agents has attracted extensive attention from academia and industry. However, the slow reaction kinetic and the weak oxidation capacity of air limits the application of this green technology. Herein, we used N-hydroxyphthalimide (NHPI) as a higdhly efficient homogeneous catalyst for the air oxidation of cyclohexanone. Through investigating the influence of reaction conditions such as temperature, gas velocity, aldehyde-ketone ratio, and solvent ratio on the conversion rate of cyclohexanone and selectivity of ε-CL, an optimum reaction condition was obtained and the ε-caprolactone production rate is as high as 3.43 mmol/gcat/min with a selectivity of 90%. The reaction mechanism is investigated through in-situ UV–visible spectra, electron paramagnetic resonance (EPR) spectra, and starch/KI experiment, and a plausible mechanistic mode involving three pivotal reactions was proposed. The dynamic model was constructed to validate the proposed mechanism and provide good predictions for the actual reaction rate. This work provides meaningful insights into NHPI-catalyzed air oxidation of cyclohexanone, and the constructed kinetic model provides theoretical guidance for scale-up processes.
研究领域:
化学工程
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催化化学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SUPERCRITICAL FLUIDS
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2014
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IF 2.571
Abdul-Rauf Ibrahim,Lihua Zhu,Jing Xu,Yanzhen Hong,Yuzhong Su,Hongtao Wang,Binghui Chen,Jun Li
A CO 2 expanded carbonation technique is proposed for direct synthesis of alumina powders that does not require structure directing substances or templates. Mesoporous amorphous flower-like alumina was synthesized at relatively low volume expansions (lower ethanol to water volume ratio), whereas mesoporous crystalline honey-comb-like alumina was synthesized at high volume expansions. The alumina powders exhibited high surface area and pore size with small crystallite sizes. The alumina structures were stable from 400 to 800 °C. Experimental tests showed that the alumina powders could catalytically convert cyclohexanone to ɛ-caprolactone efficiently. The use of the calcined catalysts (at 400 and 800 °C; flower-like alumina) at equal ethanol to water volume ratio avoids the usual and inevitable hydrolysis of ɛ-caprolactone to ɛ-hydroxyhexanoic acid. The catalyst was recyclable and stable for up to five reaction cycles.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Jianan Yu,Zhiliang Zhu,Hua Zhang,Yanling Qiu,Daqiang Yin,Yi Cheng,Shaobin Wang
Metal-free nanocarbons with versatile structural dimensions and unique properties are promising materials for remediation of polluted environment. In this work, a 3-dimensional (3D) interconnected porous N-doped carbon (CN-3) was synthesized by stepwise pyrolysis of dicyandiamide and nanocellulose, and a solid-state-growth and rolling-up mechanism was proposed for the stepwise transformation from stacking layered structures (melem and g-C 3 N 4 ) into CN-3 with 3D interconnected network nano-architectures. It was found that the functional carbons obtained at varying annealing temperature presented different activities in peroxymonosulfate (PMS) activation for endocrine-disrupting chemical (estrone) oxidation, showing temperature-dependent mechanisms from radical-dominated reaction to nonradical oxidation. CN-3 presented 100% estrone removal in 10 min, much higher than the layered carbons. In addition, CN-3 exhibited satisfactory stability during the catalytic reactions. Characterizations indicated that persistent free radicals on the layered carbons tended to induce radical reaction while graphitic structure and N in derived 3D carbons are more responsible for nonradical reaction. This work provides new insights to the relationship between the carbon structural transformation and catalytic PMS activation to induce different oxidative pathways, which facilitate the generation of a highly active and stable carbon-based catalytic system for organic degradation.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）