JOURNAL OF ORGANIC CHEMISTRY
·
2019
·
IF 4.745
Shanjian Mao,Yinbo Wan,Haiyun Peng,Li Luo,Guisheng Deng
Pd(PPh3)2Cl2-catalyzed selective tandem cyclization/oxidation of available conjugated diazo ene-yne-ketones under O2 atmosphere led to the formation of diazo trisubstituted furans. The Rh2(OAc)4-mediated selective C(sp2)–H insertion at the ortho-position of 2-aryl group (R1) of the furan moiety under N2 atmosphere occurred to construct naphthalene cycle, affording trifunctionalized naphtho[1,2-b]furans. C(sp2)–H insertion at the 4-position of the furan ring, and Wolf rearrangement of diazo moiety have not been observed.
研究领域:
有机化学
·
合成化学
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DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
·
2015
·
IF 3.615
Sheng-Jie Chen,Yong-Qi Li,Peng Wang,Yong Lu,Xiao-Li Zhao,Ye Liu
Two kinds of novel zwitterionic phosphines of L1 and L2 have been synthesized in which the sulfonate groups (–SO 3 – ) are incorporated to render them amphiphilic. Both of them are strong π-acceptor ligands in which the positive-charged imidazoliums with intensive electron-withdrawing effect are vicinal to the coordinating phosphorous atoms. The amino-group of piperidyl is additionally incorporated in L2 to make it behave as a hybrid ligand with potential hemilability. The comparison of the ligands of L1 and L2 in Rh-catalyzed hydroformylation of styrene (and its derivatives) and the effect of water on their behaviors were discussed. Without the involvement of water, the catalytic system of Rh(acac)(CO) 2 - L2 exhibited lower activity than that of Rh(acac)(CO) 2 - L1 under the same conditions. However, the dramatic promotion effect of water as a suspension was observed especially for Rh(acac)(CO) 2 - L2 system with TOF spurred up from 195 to 470 h −1 . The corresponding in situ high pressure FT-IR spectral information showed that the presence of water in Rh(acac)(CO) 2 - L2 system greatly facilitated the formation and stability of the active Rh–H species ( ν Rh-H , 2047 cm −1 ), which was in charge of the efficient hydroformylation of styrene and its derivatives.
研究领域:
有机化学
·
催化化学
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DOI
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2022
·Vol. 38
·期 5
·1258-1262
·
IF 2.726
Zhang Xingcong,Zhong Yunzhu,Chen Hongyu,Cheng Yujie,Sun Qingdi,Zhang Hao,He Qian,Zhang Ying,Guo Guanghui,He Xiaohui,Ji Hongbing
Through screening Ce precursors and pyrolysis temperatures [Ce(acac) 3 as Ce precursors and pyrolysis at 900 °C], zeolitic imidazolate framework-8(ZIF-8) derived nitrogen-doped carbon supported cerium single atom catalyst(Ce 1 /NC) is successfully prepared by ball milling method. The Ce 1 /NC catalyst exhibits exceptional catalytic performance in the selective oxidation of saturated C-H bonds in aromatic compounds, e.g. , 91% conversion and 99% selelctivity can be achieved in the oxidation of ethylbenzene to acetophenone under mild reaction conditions.
研究领域:
催化化学
·
材料科学
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DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2024
·
IF 4.8
Yuxin Li,Juanping Zhou,Hu Wen,Haitao Yin,Shunyu Han,Nanzhe Jiang
Clay is a rich aluminosilicate resource with unique advantages as a raw material for zeolites production. However, synthesizing nanosized single-crystalline zeolites through a simple approach using clay remains a significant challenge. In this paper, acid-washed montmorillonite (MSR) was used to prepare nano-H-ZSM-5 single crystals with high crystallinity, uniform grain size and permeable straight pores under the induction of a small amount of organic template tetrapropylammonium hydroxide (TPAOH). Through temperature-staged treatment, the nucleation and growth process of zeolite were decoupled, ultimately achieving precise control over the size of the nano-single crystals. Mechanistic study showed that the low-temperature aging process produces smaller structural units which probably derived from the geopolymer topology of the clay, providing more active sites for zeolite nucleation, leading to the rapid crystallization during the high-temperature process. The porous structure promotes material diffusion, inhibits aromatic cycling and reduces carbon formation in the pores. The large specific surface area and nanoscale multilayer pore structure delay carbon accumulation and increase carbon holding capacity. These properties make nano-ZSM-5 single crystals an excellent choice for high olefin selectivity and long catalytic life in the methanol-to-olefin reaction. This synthetic route provides a general strategy for preparing nanosized zeolite single crystals from clay.
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产品关联
DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Yali Niu,Rui Yao,Shuhui Fan,Jinping Li,Guang Liu
Anion-exchange membrane water electrolyzers (AEMWE) are promising for clean hydrogen production. However, the high energy barriers associated with water adsorption and dissociation combined with the high adsorption energy of hydrogen intermediates (H*) in alkaline environment result in slow kinetics for the hydrogen evolution reaction (HER). To tackle this, we report a catalyst comprising Pt nanoparticles loaded on Co(OH) 2 /PTI nanosheets (Pt/Co(OH) 2 /PTI) for efficient alkaline HER at high current densities. Operando characterization indicates that Co(OH) 2 promotes H 2 O adsorption and dissociation, while the Pt nanoparticles optimize H* adsorption energy, enabling preferential H* adsorption at the Pt site to facilitate H 2 generation and desorption. Furthermore, the ultra-thin poly (triazine imide) (PTI) support prevents the Pt nanoparticles aggregation, thereby enhancing catalyst stability. As a result, the synergistic Pt/Co(OH) 2 /PTI achieves superior HER performance, demanding an overpotential of merely 7 mV to achieve a current density of 10 mA cm −2 and just 220 mV to drive 1 A cm −2 , and it maintains stable for over 220 h under the condition of 1 A cm −2 . Additionally, the electrolyzer assembled using Pt/Co(OH) 2 /PTI as the cathode demonstrates stable operation for 200 h at 0.5 A cm −2 under 70 °C, highlighting its strong potential for industrial applications.
研究领域:
电催化
·
能源化学
·
材料科学
·
纳米催化
·
氢能技术
·
电化学工程
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产品关联
DOI
高影响因子
Catalysts
·
2019
·Vol. 9
·期 10
·869
·
IF 3.444
Xinyu Liu,Meihuan Lu,Xuan Wang,Juyou Lu,Jianxin Yang
For decades the steric effect was still ambiguously understood in catalytic benzylation reactions of arenes with benzyl alcohol, which limited the green synthesis of phenylmethane derivates in industrial scale. This research applies a series of silica–alumina beta zeolites to systematically evaluate factors like catalyst porosity, reactants molecule size, and reaction temperature on catalytic benzylation. First, a suitable hierarchical beta zeolite catalyst was screened out by X-ray powder diffraction, N2adsorption−desorption, and probe benzylation withp-xylene. In the following substrates expanding study, for a typical benzylation of benzene, it showed extraordinary performance among literature reported ones that the conversion was 98% while selectivity was 90% at 353 K only after 10 min. The steric effect of aromatics with different molecular sizes on benzylation was observed. The reaction activities of four different aromatics followed the order: benzene > toluene >p-xylene > mesitylene. Combined with macroscopic kinetic analysis, this comprehensive study points out for the first time that the nature of this steric effect was dominated by the relative adsorption efficiency of different guest aromatic molecules on the host zeolite surface.Keywords:benzylation;benzyl alcohol;hierarchical zeolite;steric effect;green catalysis
研究领域:
化学工程
·
催化科学
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Fan Zhang,Mao chen,Hailong Wang,Gang Shao,Yongshun Qi,Chengliang Ma,Bingbing Fan,Xiaoxuan Pian,Rui Zhang,Hongxia Li,Yongqiang Chen
The h-BN/ZrO 2 composites with different 3Y–ZrO 2 content were prepared by spark plasma sintering at 1800 °C. The sintering behavior , bulk density, apparent porosity , thermal conductivity , thermal expansion coefficient , bending strength , thermal shock resistance , microstructure and phase were analyzed. The optimum specimens were used to test the resistance to corrosion of molten steel for 10, 20, 40, 80 min respectively. The results indicated that ZrO 2 could facilitate the sintering process of h-BN matrix under the action of spark plasma. Especially, for the composites with 30 wt% 3Y–ZrO 2 , the porosity could decrease to 1.1% and the flexural strength could exceed 150 MPa. The microstructure showed the h-BN grains and 3Y–ZrO 2 grains are closely combined. The XRD patterns indicated that the t-ZrO 2 diffraction peak gradually enhanced with the increase of density. With the increase of erosion time, the erosion rate increased significantly. After the surface of the specimen is eroded, the erosion resistance of the matrix would decrease significantly. This h-BN/ZrO 2 could be as side-dam used in the thin strip continuous casting process .
研究领域:
材料科学
·
陶瓷工程
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DOI
高影响因子
ANALYST
·
2019
·Vol. 144
·期 13
·4086-4092
·
IF 4.019
Lili Chen,Xiangguang Li,Tongda Zou,Tiantian Wang,Xiping Cui,Yingshan Chen,Chunguo Zhang,Suqing Zhao
Given that Helicobacter pylori (H. pylori) generally infects people in early childhood and that such persons when not treated with antibiotics remain infected for the rest of their lives, it is quite important to detect H. pylori in children, and convenient to do so using non-invasive methods. Stool antigen tests constitute such an effective non-invasive method. In the current work, a novel fecal test was developed to detect H. pylori based on immunomagnetic beads (IMBs) with monoclonal antibodies sensitively recognizing and capturing the H. pylori, coupled with a polyclonal antibody-conjugating quantum dot probe, and ultrasensitive detection was achieved by using a fluorescence spectrometer. The detection method took 120 min to perform, and showed a limit of detection of 102 CFU mL−1 and a linear range of 10 to 106 CFU mL−1 (R2 = 0.9962). Most importantly, this method can be effectively applied to real samples. This study provided a novel method for the non-invasive detection of the fecal antigen H. pylori.
研究领域:
医学诊断
·
生物技术
·
分子生物学
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DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
·
2022
·
IF 6.911
Guiyin Li,Min Chen,Bo Wang,Chaoxian Wang,Guanxiong Wu,Jintao Liang,Zhide Zhou
Golgi protein 73 (GP73) is a new type of marker that can specifically detect hepatocellular carcinoma (HCC). Herein, a dual-signal sandwich-type electrochemical aptasensor for GP73 determination was constructed on the basis of hemin-reduced graphene oxide-manganese oxide (H-rGO-Mn 3 O 4 ) nanozymes. [email protected] ( o -phenylenediamine) ( [email protected] ) nanohybrids with a large specific surface area and conductance were co-electro-deposited onto a screen-printed electrode (SPE) surface to immobilize GP73 capture aptamer 2 (Apt2). H-rGO-Mn 3 O 4 nanozymes were used not only to immobilize amino functionalised GP73 aptamer 1 (Apt1) as the detection probe, but also to serve as an in-situ redox signal indicator because of the redox reaction of Hemin (Fe(Ш)/Hemin(Fe(II)). In addition, given their excellent peroxidase-like activity, H-rGO-Mn 3 O 4 nanozymes can catalyse the decomposition of H 2 O 2 and oxidation of substrate (3,3′,5,5′-tetramethylbenzidine, TMB) to oxTMB, which is used as another redox signal. In the presence of the target GP73, the two aptamers specifically bind to the target, thereby affecting two electrochemical signals. Under optimal conditions, the dual-signal sandwich-type electrochemical aptasensor had a salient analytical performance. The two electrochemical redox signals linearly increase with the logarithm of the GP73 concentration in the range of 0.01–100.0 ng/mL with the limit of detection (LOD) of 0.0071 ng/mL and sensitivity of 2.441 μA/μM/cm 2 . Moreover, the recovery of human serum samples ranged from 98.66% to 121.11%. Furthermore, the two redox signals can simultaneously corroborate each other, thereby preventing missed diagnosis and misdiagnosis. All the results can provide new insights into the clinically effective determination of HCC.
研究领域:
生物化学
·
生物技术
·
分析化学
·
癌症研究
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DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 6
Sen Liu,Shuaishuai Wu,Beibei Tang,Mao Chen,Yongqiang Chen,Hailong Wang,Rui Zhang,Bingbing Fan
High-density h-BN@SiC/ZrO 2 composites with different ZrO 2 contents were prepared by hot-pressing. The microstructure, flexural strength, thermal shock behavior, thermal expansion properties and corrosion resistance of the composites in molten steel were systematically investigated. The construction of the h-BN@SiC core-shell structure is conducive to the formation of a uniform and continuous network structure during the sintering process. This significantly improves the sintering performance of h-BN-based materials and enables the low-temperature preparation of high-density products. Moreover, the uniform distribution of SiC can effectively coordinate the thermal matching between h-BN and ZrO 2 , significantly improving the high-temperature performance of the material. During the corrosion process, the SiC network structure can effectively bind ZrO 2 and BN particles, effectively resist the erosion of high-temperature molten steel, and its erosion resistance increases with the increase of ZrO 2 content. Especially, when the ZrO 2 content reached 40%, the erosion depth of the sample was merely 160.61 μm after being immersed in static molten steel for 120 min. Moreover, the h-BN@SiC/ZrO 2 composite with 30 wt% ZrO 2 demonstrates superior comprehensive performance: It achieves a flexural strength of 159.63 MPa, retains 87.08% of its original strength after thermal shock testing, exhibits a low apparent porosity of 3.37%, and possesses an average coefficient of thermal expansion as low as 3.95 × 10 −6 /K −1 . The comprehensive properties of h-BN@SiC/ZrO 2 composites were obviously improved by SiC network structure.
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产品关联
DOI
高影响因子
GEOPHYSICAL RESEARCH LETTERS
·
2026
·Vol. 53
·期 14
·e2026GL122763
·
IF 5
Yuanjing Li,Liangliang Zhang,Fabin Pan,Xiaojing Lai,Xiang Wu,Feng Zhu
Mercury is one of the few terrestrial planets in the solar system with a magnetic field, yet the energy source to power its core dynamo remains unclear to date. Si, C, and possibly H are the top candidate light elements for its liquid core. Here, we showed experimentally that Si, C, and H in Fe-Si-C and Fe-Si-C-H liquids share a simultaneous solubility at 9–21 GPa, 1,400°C–2,200°C, and this solubility decreases with decreasing temperature. When exceeding the simultaneous solubility, light elements will exsolve from the Fe melt as elemental phases such as diamond, graphite, silicon, and H 2 . We infer that if Mercury had an early liquid core primarily composed of saturated Fe-Si-C-(H) liquid, subsequent cooling would lead to continuous light element exsolution in its liquid core. The gravitational potential released by the exsolved light elements can drive the compositional convection and power its long-term core dynamo.
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产品关联
DOI
高影响因子
CEMENT AND CONCRETE RESEARCH
·
2026
·
IF 14
Zedong Zhou,Hangxi Liu,Juanlong Li,Yiru Yan,George Dan Miron,Barbara Lothenbach,Biwan Xu,Ming Fang,Xiaoli Tan,Bin Ma
Calcium silicate hydrate (C-S-H), the principal binding phase in Portland cement, plays a critical role in the immobilization of heavy metals, yet a quantitative and mechanistic understanding of Cu 2+ uptake by C-S-H remains incomplete. This study investigates the immobilization behavior of Cu 2+ by C-S-H with systematically controlled Ca/Si ratios (0.6–1.6) and develops a thermodynamically consistent sublattice solid-solution model. The C-S-Hs were synthesized under sorption equilibrium conditions and characterized to determine their structural evolution with Ca/Si ratio. Cu 2+ sorption was subsequently examined on pre-synthesized C-S-Hs, combined with spectroscopic analyses to elucidate Cu coordination environments. The results show that Cu 2+ is immobilized predominantly through structural incorporation at low Cu 2+ loadings rather than hydroxide precipitation. With increasing Cu 2+ concentration, Cu 2+ progressively intercalates into the interlayers of C-S-H, partially replacing interlayer Ca 2+ and forming Si-O-Cu linkages associated with Q 2 silicate sites. The Ca/Si ratio strongly controls both uptake capacity and binding mechanism. High Ca/Si ratios promote silicate-chain polymerization through conversion of Q 1 to Q 2 units, whereas extremely low Ca/Si ratios induce redistribution between Q 2 and Q b 2 species. At intermediate Ca/Si ratios, Cu 2+ is mainly stabilized as hydroxyl-associated species. Once the sorption capacity is exceeded, excess Cu 2+ transforms into CuO under alkaline conditions. Based on these observations, a CASH+Cu thermodynamic model incorporating five Cu-bearing endmembers was developed and calibrated using both aqueous and solid-phase data. The model quantitatively reproduces Cu uptake, solution chemistry, and phase assemblages, providing a predictive framework for Cu 2+ retention in cementitious systems.
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DOI
高影响因子
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