EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
·
2022
·Vol. 2022
·期 33
·e202200316
·
IF 3.261
Yong Wang,Hui Wang,Qifan Yang,Shihua Xie,Hongjun Zhu
Graphical Herein, palladium(II)-catalyzed halogenation of 2-phenylquinazolines using N -halosuccinimides as halogen sources was described via C−H activation under mild reaction conditions. A series of halogen-substituted 2-arylquinazolines were synthesized through C−H functionalization. An efficient quinazoline-assisted ortho -halogenation of 2-arylquinazolines has been developed using N -halosuccinimides as halogen sources with Pd(II)-catalyzed C−H bond activation. No additional ligand and oxidant are required. This protocol is highly regioselective and applicable to a broad range of quinazoline substrates bearing different functional groups, giving yields of up to 98 %. The mechanism of the quinazoline ortho -halogenation was investigated by comprehensive experimentation.
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Journal of Biobased Materials and Bioenergy
·
2017
·Vol. 11
·期 6
·562-567
·
IF 0.975
Wang Lan-Ying,Zhuang Jun-Ping,Yu Kai-Rong,Wu Shu-Bin
Sn-Beta zeolite is a promising catalysts for isomerization of glucose to fructose, which is a key step in the conversion of biomass to various platform chemicals. Herein, Sn-Beta-H zeolite was efficiently prepared via hydrothermal synthesis by using Al-Beta. Finally, the product was
heated to 423 K for 48 h then calcined at 550 °C for 6 h to obtain Sn-Beta-H sample. The results of XRD patterns confirmed that the prepared catalyst had both microporous and mesoporous; N2 sorption isotherms showed that the main pore size centered at around 3.5 nm; TD-DTG revealed
that the Sn-Beta-H zeolite had good thermal stability with the peaks on the DTG curves was 283 °C; FTIR and UV-Vis spectra also successfully indicated that tin substitution into the zeolite framework. The effects of various reaction conditions including reaction temperature, reaction time
and the amount of catalyst on glucose conversion and fructose yield and selectivity were investigated. Under optimized operating conditions, 10% glucose solution in 40 ml water, catalyst (4 g), at 120 °C for 2 h, resulting in fructose yield of 30.8% and selectivity of 61.3%. Moreover,
Sn-Beta-H zeolite could be easily recovered and efficiently reused without significant loss in its catalytic activity.
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KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2020
·Vol. 37
·期 6
·961-968
·
IF 2.69
Dai Ping,Sun Xiaowei,Xu Dongyan,Tan Feng
Alumina supported bimetallic cobalt-iron oxide (Co 3 O 4 -Fe 2 O 3 /Al 2 O 3 ) catalyst was prepared via co-impregnation of boehmite with the mixture solution of cobalt nitrate and iron nitrate followed by calcination in air. X-ray photoelectron spectroscopy and high-resolution transmission electron microscope analyses confirmed the existence of highly dispersed Co 3 O 4 and Fe 2 O 3 nanoparticles in the as-prepared catalysts. The catalytic activity of Co 3 O 4 -Fe 2 O 3 /Al 2 O 3 was evaluated for the degradation of H-acid in aqueous solution by heterogeneous activation of peroxymonosulfate. The results indicated that the Co 3 O 4 -Fe 2 O 3 /Al 2 O 3 catalyst exhibited an identical initial activity but much better recyclability than Co 3 O 4 /Al 2 O 3 due to its low amount of metal leaching and possible redox circle of Co(II)/Co(III). Electron paramagnetic resonance spectroscopy and radical quenching experiments suggested that singlet oxygen ( 1 O 2 ) contributed much more than ·OH and SO 4 • to H-acid degradation, and the degradation mainly followed a nonradical reaction mechanism.
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高影响因子
Catalysis Science & Technology
·
2019
·Vol. 9
·期 9
·2132-2143
·
IF 5.726
Jie Zhang,Zhihua Huang,Lanjian Xu,Xiaomin Zhang,Xinzhi Zhang,Yangyang Yuan,Lei Xu
The methanol to hydrocarbons reaction over a unidimensional 10-membered-ring zeolite, H-ZSM-48, was investigated in the temperature range of 723–973 K. C3–5 olefins were the dominant products of reaction at 723 K. Multiple approaches (constant, transient, co-feed and isotope labelling experiments) have been adopted to clarify the underlying reaction pathway. The results indicate that both of the olefin- and aromatics-based cycles contribute to light olefin formation, and the aromatics-based cycle can be significantly enhanced with increasing reaction temperature. Ethene is formed predominantly from the aromatics-based cycle while propene and higher olefins are mainly derived from the olefin-based cycle. The 12C/13C-methanol isotopic switching experiments manifest that hexamethylbenzene is the most active aromatic intermediate. Co-feeding of 13C-methanol and 12C-benzene at 543 K reveals that the paring mechanism is the dominant mechanism for aromatic dealkylation. More importantly, the first experimental evidence that the two carbons of ethene are derived from aromatic ring carbons is obtained based on the isotopic pattern. Furthermore, the investigation on coke-covered H-ZSM-48 reveals that the reaction of methylbenzenes occurs mainly inside the channels. This work will shed new light on the reaction pathway of the MTH reaction over unidimensional zeolites.
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高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Kunpeng Qian,Qianfan Zhou,Sineenat Thaiboonrod,Jianhui Fang,Miao Miao,Hongmin Wu,Shaomei Cao,Xin Feng
With the development of electronic equipment, heat problem and electromagnetic pollution severely affect both their functions and human health, which leads to great interests in developing materials synchronously with outstanding thermal conductivity and electromagnetic interference (EMI) shielding performance. Here, ultrathin Ti 3 C 2 T x /h-BN two-dimensional (2D) heterostructure films were prepared via coulombic assembly between Ti 3 C 2 T x MXene and h-BN nanosheet through ultrasonic blending. After the addition of h-BN nanosheet as thermal conductive nanofillers, the hybrid films achieved a higher value of thermal conductivity, compared to Ti 3 C 2 T x composite film without h-BN. The higher thermal conductivity offered by h-BN enables the Ti 3 C 2 T x /h-BN films have good potential for EMI shielding applications on wearable and portable electronic devices. When the mass ratio of Ti 3 C 2 T x /h-BN is 7:3, the hybrid film with the thickness of 47.60 µm exhibited electrical conductivity of 57.67 S/cm and the maximum EMI shielding effectiveness of 37.29 dB.
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JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Yong Zhou,Jiamei Liu,Xudong Zhao,Bin Yang,Bing Li,Xiaoyang Liu
Because of their unique electrical and magnetic properties, the perovskite multiferroic materials exhibit significant potential in spintronic device applications. However, synthesizing room-temperature multiferroic materials with robust magneto-electric coupling effects remains a major challenge. In this work, Yb 3 + , with an ionic radius slightly smaller than Y 3+ , was selected for A -site doping in the h -YMnO 3 , which has a high ferroelectric transition temperature (T C ∼ 900 K) and a low antiferromagnetic transition temperature (T N ≤ 70 K). This similar ionic radius allows Yb to substitute the Y site effectively while introducing distinct electronic states, thereby optimizing the structure and multiferroic properties of h -YMnO 3 without significantly altering the crystal structure. A series of Yb-doped Y 1- x Yb x MnO 3 ( x = 0, 0.1, 0.2, 0.3, 0.4, 0.5 and 1) materials were synthesized via conventional solid-phase reaction. The effects of Yb doping on the structure, magnetism, and ferroelectricity of h -YMnO 3 were studied. X-ray diffraction (XRD) and corresponding XRD refining results show that as Y 3+ is replaced by Yb 3+ with smaller radii, the cell parameters and cell volume of Y 1- x Yb x MnO 3 decrease, the cell is compressed, and the lattice structure of Y 0.5 Yb 0.5 MnO 3 obtained under the condition of Yb semi-doping changes significantly. Subsequent magnetic and room-temperature ferroelectric test results show that the Y 1- x Yb x MnO 3 series samples have anti-ferromagnetic ground states. In particular, the proper inclination of Mn 3+ ions in the double perovskite structure of Y 0.5 Yb 0.5 MnO 3 generates strong Dzyaloshinskii-Moriya (DM) interactions, resulting in relatively strong antiferromagnetism. The antiferromagnetic Neel temperature (T N ) from 37 K to 41 K. Yb 3+ -induced inclined ferroelectricity enables Y 0.8 Yb 0.2 MnO 3 to achieve the highest ferroelectric polarization of 0.030 µC cm −2 , which is 180 % greater than that of h -YMnO 3 . The results demonstrate that Yb doping plays a crucial role in regulating the structure and multiferroic properties of h -YMnO 3 , offering a novel strategy for developing room-temperature multiferroic materials with robust magneto-electric coupling.
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产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Mengwei Han,Yuzhu Qian,Xinni Li,Nailiang Wang,Ting Song,Li Liu,Xianyou Wang,Xiongwei Wu,Man-Kay Law,Bei Long
Developing insertion-type anode is key to advancing “rocking chair” zinc-ion batteries, though there are few reported insertion-type anodes. Herein, the Bi 2 O 2 CO 3 is a high-potential anode, with a special layered structure. A one-step hydrothermal method was used to prepare Ni-doped Bi 2 O 2 CO 3 nanosheet , and also a free-standing electrode consisting of Ni-Bi 2 O 2 CO 3 and CNTs was designed. Both cross-linked CNTs conductive networks and Ni doping improve charge transfer. Ex situ tests (XRD, XPS, TEM, etc.) reveal the H + /Zn 2+ co-insertion mechanism of Bi 2 O 2 CO 3 and that Ni doping improves its electrochemical reversibility and structural stability. Therefore, this optimized electrode offers a high specific capacity of 159 mAh g −1 at 100 mA g −1 , a suitable average discharge voltage of ≈0.400 V, and a long-term cycling stability of 2200 cycles at 700 mA g −1 . Besides, the Ni-Bi 2 O 2 CO 3 //MnO 2 “rocking chair” zinc-ion battery (based on the total mass of cathode and anode) delivers a high capacity of ≈100 mAh g −1 at 50.0 mA g −1 . This work provides a reference for designing high-performance anode in zinc-ion batteries.
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高影响因子
APPLIED CATALYSIS A-GENERAL
·
2021
·
IF 5.706
Mingyang Tan,Liang Zhu,Hao Liu,Yajun Fu,Shuang-Feng Yin,Weijun Yang
A Cobalt porphyrin conjugated porous polymer (Co/PCP) was obtained by hybrid polymerization of a mixture of Co(II)(5,10,15,20-tetrakis(4-bromophenyl)-21H,23H-porphyrin) (CoTBPP) and 5,10,15,20-tetrakis(4-bromophenyl)-21H,23H-porphyrin (TBPP) (3:7 M ratio) with the coupling reagent of p-phenyldiboric acid. This Co/PCP was carbonized at 400 °C and the obtained catalyst (denoted as Co 3 O 4 @PNC-400) was composed of Co 3 O 4 nanoclusters wrapped in the nitrogen-carbon materials. This catalyst has an extremely high catalytic activity for the aerobic oxidation of C–H bonds. It can efficiently catalyze the oxidation of the C–H bonds in toluene and cyclohexane with high conversion and high selectivity of (alcohol + aldehyde), (alcohol + ketone) compounds, respectively. When heat-treated at 400 °C, the porous framework structure of the porphyrin polymer was partially retained, and the highly active Co 3 O 4 nanoclusters were generated in situ. The reaction of C N to C N and connection with the Co 3 O 4 nanoclusters also occurred. Co 3 O 4 @PNC-400 has obvious synergistic catalytic effect between Co 3 O 4 and nitrogen-carbon framework during the catalytic reaction. The defective structure caused by the migration of cobalt also greatly improved the catalytic activity. Co/PCPs with different cobalt contents were also synthesized and heat treated at different temperature. These catalysts were a new type of efficient C–H oxidation catalysts with excellent potential application value.
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CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Yunzi Li,Fei Chen,Xiaoyu Li,Qiang Shen,Lianmeng Zhang
Ceramic/metal composites, as high-temperature structural materials, have limited applications because of their poor machinability . AlN/Mo/Mo 2 B machinable composites were fabricated by adding h-BN to AlN/Mo composites by plasma-activated sintering at various temperatures and at an axial pressure of 30 MPa under argon atmosphere. The sample sintered at 1500 °C exhibited excellent machinability for cemented carbide tools, with a bending strength of approximately 500 MPa and a Vickers hardness value of 9.34 GPa. The effects of sintering temperature on the microstructure, mechanical properties, and machinability were investigated, and the reactions introduced by adding h-BN were studied. These reactions reinforced the composite and newly introduced a Mo 2 B phase, which showed better ability to deflect cracks and prevent them from moving deep inside the composite, thus improving its machinability. This research provides a possible solution for improving the machinability of ceramic/metal composites without sacrificing the strength .
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Journal of Energy Chemistry
·
2020
·
IF 7.216
Libin Wang,Ting Shu,Songtao Guo,Shi Chen,Yingjun Jiang,Xianluo Hu
ABSTRACT Owing to sluggish ionic mobility at low temperatures, supercapacitors , as well as other energy-storage devices, always suffer from severe capacity decay and even failure under extreme low-temperature circumstances. Solar-thermal-enabled self-heating promises an attractive approach to overcome this issue. Here, we report a unique H-bonding charge-transfer complex with a high photothermal conversion efficiency of 79.5% at 405 nm based on chloranilic acid and albendazole . Integrated with a microsupercapacitor, the chloranilic acid-albendazole complex (CAC) film prompts an apparent temperature increase of 22.7 °C under 1 sun illumination at −32.6 °C, effectively elevating the working temperature of devices. As a result, the rate capability of the microsupercapacitor has been significantly improved with a 17-fold increase in capacitance at a current density of 60 μA cm −2 , leading to outstanding low-temperature performances. Importantly, the integrated device is capable of working at a low temperature of −30 °C in the open air, which demonstrates the potential of CAC in practical applications for low-temperature ultracapacitive energy-storage devices.
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Advanced Science
·
2024
·
IF 14.3
Lijiao He,Xiao Zhang,Shengwei Zhang,Yi Wang,Weichao Hu,Jie Li,Yunyi Liu,Yu Liao,Xue Peng,Jianjun Li,Haiyan Zhao,Liting Wang,Yang-Fan Lv,Chang-Jiang Hu,Shi-Ming Yang
Persistent H. pylori infection triggers the repair program of the mucosa, such as spasmolytic polypeptide-expressing metaplasia (SPEM). However, the mechanism underlying the initiation of SPEM in gastric tissues by H. pylori remains unclear. Here, an increase in telomerase reverse transcriptase (TERT) protein expression is observed in chief cells upon infection with cagA -positive H. pylori . Tert knockout significantly ameliorated H. pylori -induced SPEM and single-cell RNA sequencing demonstrated that the Wnt/β-Catenin pathway is suppressed in gastric cells with Tert knockout. Mechanism study revealed that CagA elevated TERT abundance by disrupting the interaction between TERT and its novel E3 ligase, SYVN1. Interestingly, Nitazoxanide effectively relieved SPEM via inhibition of the Wnt/β-Catenin signaling in vivo. This results clarified the mechanism underlying which CagA activated the TERT/Wnt/β-Catenin pathway, thus promoting the dedifferentiation of chief cells and the occurrence of SPEM in gastric mucosa. This highlights a molecular basis for targeting CagA-activated Wnt signaling in chief cells for the treatment of gastric precancerous lesions.
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PubMed
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2014
·Vol. 28
·期 9
·673-677
·
IF 2.017
Limin Ren,Wenyi Chu,Dinghui Guan,Yanjun Hou,Man Wang,Xiaobin Yuan,Zhizhong Sun
A simple and efficient route for the preparation of terphenyl derivatives via palladium-catalyzed sequential directed C―H arylation/Suzuki–Miyaura cross-coupling in ‘one-pot’ has been developed. 4,4′-(Cyclohexane-1,1-diyl)diphenol is an essential ligand. This reaction can tolerate a series of functional groups and provides the terphenyl derivatives in moderate to good yield. Copyright © 2014 John Wiley & Sons, Ltd.
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