Molecular Catalysis
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2022
·
IF 5.089
Nan Li,Changping Jian,Yaping Song,Li Wang,Ata Ur Rehman,Yanghe Fu,Fumin Zhang,De-Li Chen,Weidong Zhu
Herein, we reported a facile and scalable approach for the synthesis of Fe-based MOF MIL-88A(Fe) via a simple liquid-phase route at atmosphere pressure, and its application as a heterogeneous catalyst for the efficient aerobic oxidation of cyclohexene to value-added 2-cyclohexene-1-ol. Over 130 g of spindle-shaped MIL-88A(Fe) nanocrystals with high crystallinity, monodispersed particle size, and large specific surface area were easily synthesized per batch according to our method. The resultant MIL-88A(Fe) exhibited a high catalytic activity (conversion: 81%) with 70% selectivity for 2-cyclohexene-1-ol in the aerobic oxidation of cyclohexene with O 2 as the sole oxidant under mild reaction conditions (0.5 MPa of O 2 , 353 K for 8 h), outperforming the analogues reported in the literatures. The combined experimental and theoretical approach support the reaction mechanism of the oxidation of cyclohexene via both the free radical reaction pathway and Fe-mediated reaction pathway, resulting in the selective formation of 2-cyclohexene-1-ol.
研究领域:
材料科学
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催化化学
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有机合成
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DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 108
·107104-107108
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IF 3.289
Y. N. Wei,H. Li,F. Yue,Q. Xu,J. D. Wang,Y. Zhang
Herein, we introduce a new strategy towards the cyclohexene oxidation reaction, which is driven by molecular oxygen with a cobalt(II)/amine acid complex as the catalyst without any solvents. The as-prepared products include cyclohexene oxide, 2-cyclohexene-1-ol and 2-cyclohexene-1-one. Under optimized conditions, the oxidation of cyclohexene with molecular oxygen yields a conversion rate of 82.5%. Notably, the catalytic oxidation system has the advantages of being clean, safe and operationally simple. Our experiment indicates that the oxidation follows a radical-chain mechanism rather than a catalytic mechanism, which reveals that 2-cyclohexene-1-hydroperoxide could play a key role in the free-radical chain reaction through a complicated but necessary product analysis.
研究领域:
有机化学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2023
·Vol. 47
·期 8
·3936-3944
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IF 3.3
Binxiong Guang,Yiwei Zhang,Yahui Xiao,Miaojun Su,Yong Liu
To bridge transition metal complexes and heterogeneous catalysts for allylic oxidation of cyclohexene to 2-cyclohexene-1-one with O2 under mild conditions, Cu(II) coordinated N-bearing heteropolyacid-based poly(ionic liquid)s (Cu-PDVD-PW) were herein synthesized as novel heterogeneous catalysts. The physicochemical properties of the catalysts were investigated by BET, TG, XPS, FT-IR and SEM/EDS analysis. The results indicated that the as-prepared Cu-PDVD-PW catalyst inherited appreciable mesopores and excellent thermal stability from the N-bearing poly(ionic liquid)s, which could increase the mass transfer rate and provide more accessible active sites. Significantly, the Cu2+ cations were homogeneously and stably coordinated on the N-bearing poly(ionic liquid)s, which greatly improved the catalytic performance for cyclohexene oxidation toward 2-cyclohexene-1-one with O2 under mild conditions. Specifically, the 3% Cu-PDVD-PW catalyst exhibited 75.9% conversion of cyclohexene with a selectivity towards 2-cyclohexene-1-one of 45.5% and no activity loss within five cycles under the optimum reaction conditions.
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
Nano Research
·
2024
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IF 9.5
Guo Xu,Song Liru,Wang Wenyu,Li Fengfeng,Ha Minh Ngoc,Tang Jun,Ling Qiang,Cui Ping,Ke Qingping
Heterogeneously catalyzed liquid oxidation of olefins with O 2 provides an alternative way for synthesizing high-value added chemicals. Herein, we report a straightforward urea-redox and sol-gel process for synthesizing LaCo x Cu 1− x O 3 for aerobic photo-oxidation of cyclohexene. Our research highlights a marked increase in the proportions of Co 2+ and Cu + species in a low chemical state, as well as enhanced visible light absorption through this method. Mechanistic investigations suggest that the catalytic process, particularly with LaCo 0.7 Cu 0.3 O 3 , involves a radical pathway mediated by reactive oxygen species. The presence of Cu + /Co 2+ species and surface oxygen vacancies is proposed to boost O 2 adsorption and activation on the catalyst, facilitating the formation of 2-cyclohexene-1-hydroperoxides. Furthermore, Cu 2+ /Co 3+ species are thought to aid in generating cyclohexene-derived radical species. The efficient aerobic oxidation of cyclohexene on LaCo 0.7 Cu 0.3 O 3 catalyst relies on the formation of reactive oxygen species and carbon radicals, facilitated by its strong visible light illumination. It achieves a cyclohexene conversion of 89.4% and selectivity to cyclohex-2-ene-1-one of 72.2%, along with stable recyclability after six reuses. The creation of nano-structured LaCo x Cu 1− x O 3 through the urea-redox and sol-gel process offers a promising avenue for the development of highly efficient catalysts for the aerobic photo-oxidation of cyclohexene to cyclohex-2-ene-1-one in the future.
研究领域:
化学工程
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材料科学
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DOI
高影响因子
POLYMER
·
2014
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IF 3.766
Ming Luo,Xing-Hong Zhang,Bin-Yang Du,Qi Wang,Zhi-Qiang Fan
This paper describes the first example of alternating copolymerization of carbonyl sulfide (COS) with cyclohexene oxide (CHO) via heterogenous catalysis of a nano-lamellar zinc–cobalt(III) double metal cyanide complex (Zn–Co(III) DMCC), providing an efficient method for converting COS to poly(cyclohexene monothiocarbonate) (PCHMTC) with an alternating degree up to 93%. The number-average molecular weight ( M n ) of PCHMTC was 6.5–25.0 kg/mol with polydispersities (PDIs) of 1.6–2.1. The productivity of the catalyst was up to 970 g polymer/g catalyst (5.0 h). The oxygen–sulfur exchange reaction (O/S ER) caused by Zn–Co(III) DMCC was largely suppressed when the reaction was performed at 100–110 °C in the presence of THF or CH 2 Cl 2 , and thus the selectivity of the monothiocarbonate over carbonate linkages was up to 98%. The mechanisms of the copolymerization and O/S ER were proposed based on the ESI-MS, GC–MS and FT-IR spectra. The obtained PCHMTC is highly transparent and exhibits good solubility in various organic solvents , high T g of 112 °C, initial decomposition temperature of 214 °C and high refractive index of 1.705.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Shihao Su,Guojun Lv,Jialing Shen,Fuxin Wang,Lachgar Oussama,Yan Chen,Shengnan Xu
In the tandem synthesis of 1,2-cyclohexanediol, solvents such as acetonitrile are often added to eliminate the immiscibility of cyclohexene with water and accordingly strengthen the interphase mass transfer; however, the usage of solvents artificially increases the solvent separation procedure, enhancing the energy consumption and decreasing the economic benefits of the reaction process. Hence, the development of the solvent-free Pickering interfacial tandem catalysis of cyclohexene to 1,2-cyclohexanediol is extremely appealing. In this study, β-MnO2 and Mn2O3 were prepared by calcining γ-MnO2 synthesized with the hydrothermal synthesis method and concurrently served as a colloidal emulsifier and a heterogeneous catalyst in the Pickering interfacial tandem catalysis of cyclohexene to 1,2-cyclohexanediol at room temperature in the presence of the oxidant molecular oxygen and the co-oxidant isobutyraldehyde. The prepared β450-MnO2 sample revealed the best tandem catalysis performance, achieving a cyclohexene conversion of 99.4% and a 1,2-cyclohexanediol selectivity of 83.6% within 4 h of reaction, which can be ascribed to the highest Mn4+/Mn3+ ratio and the greatest concentration of oxygen vacancies as well as the most stable Pickering emulsion. At the same time, density functional theory (DFT) studies further confirmed that isobutyraldehyde and molecular oxygen could be more easily adsorbed and activated by β450-MnO2 in comparison with the other catalyst samples, benefiting its eminent catalytic epoxidation performance. In addition, a possible reaction mechanism for the β450-MnO2 catalyst catalyzing cyclohexene into 1,2-cyclohexanediol in the Pickering interfacial tandem catalytic reaction system was put forward and validated through quenching experiments as well as in situ infrared characterization. The synthesized β450-MnO2 catalyst exhibited reusability for greater than 5 cycles, and meanwhile, the Pickering interfacial tandem catalytic reaction system can be expanded to a spread of linear and cyclic alkene substrates, highlighting the superiority of the β450-MnO2 catalyst. These findings verify that the synthesized β450-MnO2 catalyst is capable of being utilized as an efficient and stable catalyst for the Pickering interfacial catalytic conversion of alkenes into 1,2-diols at room temperature.
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
CATALYSIS LETTERS
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2022
·Vol. 153
·期 3
·836-849
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IF 2.936
Jiang Haoran,Xue Changhao,Sun Weijie,Gong Zhaoxiang,Yuan Xia
The esterification of cyclohexene with formic acid is the first step in synthesizing cyclohexanol via the indirect hydration of cyclohexene. In this work, we improved the efficiency of the esterification reaction by constructing a sulfonic-acid-functionalized UiO-66 solid-acid catalyst containing defect sites. By using acetic acid as the modulator, ZrCl 4 as the zirconium source, and 2-sulfoterephthalic acid monosodium salt as the ligand, a sulfonic-acid-functionalized UiO-66-SO 3 H with defect sites was prepared using a solvothermal synthesis method. Additionally, we also prepared UiO-66 with defect sites for comparison. We then investigated the regulation effects of acetic acid addition amount on the defect structures and acidity of the as-prepared materials. The results showed that the addition of acetic acid caused lattice defects in the as-prepared materials with a missing linker, and the specific surface area, pore volume, pore size, and particle size of the material changed significantly. The number of defect sites was determined by thermogravimetric analysis. Additionally, pyridine infrared spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis indicated that the ratio of Lewis acid to Brønsted acid sites, and the total acid content in the defect materials, greatly increased compared to pure UiO-66 and UiO-66-SO 3 H, which greatly enhanced the acid catalytic performance of the material. Among these, UiO-66-SO 3 H(20), which was prepared by adding 20 mL of acetic acid, exhibited the best catalytic activity. The conversion rate of cyclohexene reached 83.4%, the selectivity toward cyclohexyl formate was 99.8%, and the catalyst could be reused three times. Graphical Abstract The purpose of this work was to improve the efficiency of the esterification reaction of cyclohexene with formic acid by constructing a sulfonic acid-functionalized UiO-66 solid acid catalyst containing defective sites. The regulation effect due to the amount of acetic acid added on the defect structure and acidity of the as-prepared materials was investigated.
研究领域:
化学
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催化材料
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2015
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IF 3.52
Fuping Tian,Zhikai Fu,Huan Zhang,Jianjun Zhang,Yongying Chen,Cuiying Jia
Adsorption desulfurization is one of the most promising ways to reduce the sulfur content of gasoline at deeper level. In this work, thiophene (TP) adsorption capacity in cyclohexane onto [Cu 3 (BTC) 2 (H 2 O) 3 ] (HKUST-1) was measured by batch method, and the effect of cyclohexene and toluene on sulfur capacity was investigated. Adsorption isotherms of TP, cyclohexene, and toluene in cyclohexane onto HKUST-1 were conducted at 298.15–313.15 K to explicate the different extent of influence by cyclohexene or toluene addition. The results showed that, compared with cyclohexene, the addition of toluene in model gasoline led to a moderate decline in sulfur capacity of HKUST-1. The isotherm data of TP adsorption were well-correlated using Langmuir equation, while those of cyclohexene or toluene adsorption fitted Freundlich model, indicating different adsorption mechanisms between TP and competitors. The adsorption capacities followed the order of toluene < cyclohexene ≪TP at the same equilibrium concentrations, implying the order of the adsorption affinities, which is in good agreement with the different extent of influence by cyclohexene and toluene. The excellent regeneration performance of HKUST-1 in TP adsorption benefits from the physical adsorption mechanism, which was hinted by the enthalpy of TP adsorption (−37.31 ± 2.04 kJ mol −1 ) and no detection of new sulfur species.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2024
·
IF 9.4
Yan Chen,Guojun Lv,Xuyang Zou,Shihao Su,Jiangzhang Wang,Chaoyi Zhou,Jialing Shen,Yangbin Shen,Zhongmin Liu
Dealuminated Beta zeolite has a large amount of silanol defects on its interface, which provides an ideal place for embedding metal species and creating metal active sites in a confined microenvironment. The confined metal sites as well as their surroundings are closely related to the reactant activation and transient state achievement. Hence, unraveling the confined metal sites is of great significance for the catalytic reaction process. Herein, niobium species were incorporated into the silanol defects over dealuminated Beta zeolite with a facile dry impregnation method, co-grinding the niobium precursor with dealuminated Beta zeolite support. The successful incorporation of niobium into the silanol defects for 30Nb-Beta zeolite was verified by DRIFT, 1 H MAS NMR, UV–Vis and UV-Raman characterizations. XAS characterization and DFT calculations further disclosed that the confined Nb species existed as (SiO) 2 Nb(OH)(=O), containing two Si−O−Nb bonds, one Nb=O bond as well as one Nb−OH bond. The synthesized 30Nb-Beta zeolite catalyst displayed a superior cyclohexene conversion of 51.1%, cyclohexene oxide selectivity of 83.1% as well as TOF value of 188.2 h −1 ascribed to the inherent electrophilicity of Nb(V) for confined (SiO) 2 Nb(OH)(=O) species as well as the low oxygen transfer energy barrier for Nb V −OOH species. Furthermore, the prepared 30Nb-Beta zeolite can be effectively employed to other cyclic alkene epoxidation reactions.
研究领域:
催化化学
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材料科学
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产品关联
DOI
PubMed
高影响因子
CHEMICAL PAPERS
·
2017
·Vol. 72
·期 3
·643-649
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IF 1.258
Wang Bingtong,Zhang Zongbin,Zhang Xinyu,Sun Shixin,Wu Lin,Xing Rong
A simple, efficient, and eco-friendly catalytic system for the oxidation of cyclohexene to adipic acid with H 2 O 2 catalyzed by H 2 WO 4 in Brønsted acidic ionic liquids under solvent-free conditions has been developed. Reaction conditions such as the catalysts, the types of anions and cations for Brønsted acidic ionic liquids, reaction temperature, and the amount of hydrogen peroxide, were investigated. Moreover, the Hammett acidity functions ( H
0 ) of Brønsted acidic ionic liquids were determined using UV–visible spectrophotometry. The optimum reaction condition identified was n(H 2 WO 4 ):n(Brønsted acidic ionic liquids): n (cyclohexene): n (H 2 O 2 ) = 0.02:0.02:1:4.4, and the yield of adipic acid was 96% under the reaction scale of 10 mmol. The catalytic system can be easily recovered and reused for four reaction runs without significant loss of catalytic activity. Simple operation of the catalyst system and avoidance of the emission of nitrous oxide are the benefits of this work.
研究领域:
化学
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环境科学
✓ 已验证
DOI
高影响因子
ChemCatChem
·
2017
·Vol. 9
·期 21
·4139-4147
·
IF 4.803
Yuexiao Song,Feng Xin,Lexiang Zhang,Yong Wang
Graphical That′s radical ! In the homogeneous catalytic oxidation of cyclohexene by transition-metal-substituted phosphotungstates with hydrogen peroxide, allylic oxidation and epoxidation proceed through radical pathways based on transition metals and nonradical pathways based on PW 4 , respectively. Homogeneous catalytic oxidations of cyclohexene by transition-metal-substituted phosphotungstates [PW 11 M(L)O 39 ] m− (PW 11 M, M=Co II , Cu II , Fe III , Ni II , Mn II , L=H 2 O or absence) with hydrogen peroxide in acetonitrile were experimentally studied. The catalytic activities of allylic oxidation were found to strongly depend on the transition metals, and PW 11 Co showed the highest activity. The product distribution and the catalyst stability were dominated by mole ratio of hydrogen peroxide to PW 11 M, whereby low or high mole ratios led to stable structure of PW 11 M and predominant formation of allylic oxidation products or decomposition of PW 11 M, respectively. Different from the activation of the allylic C−H bond by radicals, the oxidation of C=C double bond was based on tungsten-peroxo species. A reaction mechanism composed of radical and nonradical processes was proposed from NMR, EPR, and kinetic data, to describe the reaction pathways of cyclohexene oxidation.
研究领域:
化学
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催化反应
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2025
·
IF 9.5
Chang'an Wang,Zuoshuai Xi,Tao Ban,Zhiyuan Liu,Yibin Luo,Hongyi Gao,Ge Wang,Xingtian Shu
The fine design and regulation of the microenvironment surrounding active sites in metal–organic frameworks (MOFs) are crucial for optimizing electron distribution and enhancing oxygen activation, thereby achieving superior catalytic performance in epoxidation reactions. In this study, we focus on the synergistic modulation of the cobalt (Co) microenvironment in MOF-74 through the introduction of lanthanum (La) sites and defect engineering. The incorporation of rare-earth La species effectively redirects the electron density of Co sites, enhancing their oxygen activation capabilities. Additionally, the presence of coordination-unsaturated Co sites facilitates rapid electron transfer from active sites to substrates, promoting the generation of superoxide radicals. Notably, the Co0.50La0.50-MOF-74-4eq sample demonstrates exceptional molecular oxygen utilization and epoxidation performance, achieving a cyclohexene conversion of 92.2% with a selectivity of 93.9% for 1,2-epoxycyclohexane at 40 °C within 1 hour. Furthermore, this catalyst exhibits broad applicability across different substrates. Density functional theory calculations, complemented by in situ analysis, confirm that molecular oxygen activation occurs at Co sites while suppressing the allylic oxidation pathway, thus favoring the conversion of cyclohexene to epoxides. This work elucidates how strategically tailoring the electronic properties around catalytic sites can dramatically influence catalytic behavior in heterogeneous catalysis, providing new insights for the rational design of advanced catalysts.
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）