RSC Advances
·
2015
·Vol. 5
·期 125
·103203-103209
·
IF 3.84
Qin Zhang,Po Yang,Yuyuan Deng,Chengxi Zhang,Rongqi Zhu,Yi Gu
This work aims to search the key starting materials and the key step of benzoxazine synthesis using primary amine, phenol and formaldehyde as the starting materials. The reaction kinetics were investigated by gas chromatography. The kinetic parameters of benzoxazine formation, such as reaction order, rate constant and activation energy, were found to approximately equal those of phenol consumption, which revealed that phenol was the key starting material and played an important role in the synthesis of benzoxazine. Furthermore, step 2, the reaction between formaldehyde–amine derivatives and phenol for the production of a mannich base was the controlling step. This improved insight into the benzoxazine synthesis is expected to help researchers explore novel benzoxazines and control their synthesis.
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2014
·
IF 4.086
Ping Geng,Jingyang Su,Caroline Miles,Christos Comninellis,Guohua Chen
Pure Magnéli Ti 4 O 7 nanotube arrays (NTA) were successfully fabricated by reducing TiO 2 NTA with hydrogen at 850 °C for 30 minutes. The microstructure, composition and electrochemical behavior of the prepared Ti 4 O 7 NTA were characterized by means of X-ray Diffraction, Scanning Electron Microscopy, Transmission Electron Microscopy , X-ray Photoelectron Spectroscopy, Cyclic Voltammetry and Electrochemical Impedance Spectroscopy . The as-prepared Ti 4 O 7 NTA had a highly-ordered tubular structure with high crystallinity , large electrochemical window of water electrolysis (2.4 V vs. Ag/AgCl, pH = 6.0) and low interfacial charge transfer resistance when they were employed as anode for electro-oxidation. Phenol was electro-oxidized on Ti 4 O 7 particles and Ti 4 O 7 NTA with the latter giving 20% more Chemical Oxygen Demand (COD) removal. Pure Ti 4 O 7 NTA also displayed larger degradation coefficient as well as higher COD removal and current efficiency than Boron-doped Diamond and other types of Magnéli NTAs. Cathodic polarization was found to be an effective way of restoring the electrochemical performance of oxidized Ti 4 O 7 NTA as an anode.
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2014
·
IF 5.9
Wei Wei,Yu Zhao,Shichao Peng,Haoyang Zhang,Yipeng Bian,Hexing Li,Hui Li
In this paper, we develop a facile strategy for fabricating a yolk–shell structured catalytic system that consists of a core made of Ru supported on mesoporous carbon, which is encaged within a silica shell that has ordered radial mesochannels. A region-selective etching mechanism for the formation of the yolk–shell nanoarchitectures is proposed based on the stronger adsorption ability of the carbon core for etching agent than that of the silica shell for etching agent. By combining such material with amyloglucosidase, one-pot hydrolysis–hydrogenation of dextrin to sorbitol can be conducted, delivering enhanced efficiency and showing great promise for biomass conversion applications.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ChemElectroChem
·
2017
·Vol. 4
·期 9
·2359-2365
·
IF 4.136
Chengwei Zhang,Zheng Zhang,Fuxing Yin,Yongguang Zhang,Almagul Mentbayeva,Moulay-Rachid Babaa,Anara Molkenova,Zhumabay Bakenov
Graphical Picking holes in carbon : A ZnO/3DOMC composite was prepared by deposition of ZnO nanoparticles on 3DOMC (three dimensionally ordered macroporous carbon). The material exhibited ordered macropores and mesopores and demonstrated high specific capacity and stable cycling performance as an anode for Li-ion batteries. A one-step template-based technique for the fabrication of three dimensionally ordered macroporous carbon (3DOMC) was developed. 3DOMC, prepared using silica crystal as a template and soluble resol as a carbon source, possesses ordered macropores with mesoporous walls. ZnO nanoparticles were deposited on as-prepared 3DOMC via a simple in situ growth process to form a ZnO/3DOMC anode material for lithium-ion batteries. In the composite, the ZnO nanoparticles (≈3.9 nm) were well-dispersed on the walls of 3DOMC. The ZnO/3DOMC anode exhibited an enhanced performance in a lithium battery delivering a specific capacity of 673 mAh g −1 at a current density of 0.1 C (0.1 C=97.8 mA g −1 ) after 300 cycles. This superior performance was ascribed to the ordered interconnected macropores of 3DOMC which could provide rapid diffusion paths for lithium-ion diffusion and the electrolyte penetration, and buffer the volume changes of the ZnO nanoparticles upon cycling. Furthermore, the mesoporous structure of the 3DOMC walls could enhance the wettability of the ZnO-based electrode, further improving its electrochemical performance.
✓ 已验证
产品关联
DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2017
·
IF 2.473
Congfei Yao,Yucui Hou,Shuhang Ren,Youan Ji,Weize Wu
Phenols are important materials for the organic chemical industry. They mainly come from coal liquefaction oil, coal tar, petroleum and biomass pyrolysis oil, making the separation of phenols from oil mixtures of great commercial value. Two zwitterionic alkaloids, betaine and L-carnitine, biodegradable and environmentally benign ionic compounds , can efficiently separate phenols from oils by forming deep eutectic solvents (DESs). In this work, the phase equilibria of two ternary systems of toluene + phenol + betaine and toluene + phenol + L-carnitine were measured at 25.0 °C, 45.0 °C and 65.0 °C under atmospheric pressure. The phase behaviors of the two ternary systems were studied, which indicated that there were three kinds of phase regions: liquid, liquid-liquid, and liquid-liquid-solid. The separation of phenol from oil mixtures occurs at the latter two phase regions. Effects of temperature, zwitterionic alkaloid type and its dosage on the phase equilibrium were investigated. With decreasing temperature, the distribution and selectivity coefficients increase. L-carnitine shows better performance in separating phenol from oils via forming DES than betaine.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2025
·
IF 6.2
Wen-Ao Shi,Zhong-Hao Jiang,Ni Bai,Ai-Min Wang,Ai-Rong Mao,Zi-Long Zhao,Lin Lang,Jian Wei,Hai-Yan Liu,Qing-Qing Sun,Yong Gao,Yu-Hong Kang,Yan-Jun Li,Jin-Jun Bai
The separation of condensed aromatic compounds from coal tar residue (CTR), converted into cyclanes via catalytic hydroconversion (CHC) to produce essential blending components for coal-based jet fuel, represents a significant strategy for enhancing CTR's value. A highly efficient bifunctional catalyst was prepared by loading Ni nanoparticles (NNPs, ca . 10 %) on β /MCM-41 composite zeolite ( β / M) and denoted as Ni 10 % @ β / M . CTR was sequentially extracted with acetone/carbon disulfide, petroleum ether, and petroleum ether/methanol (5 vol% H 2 O) to obtain the soluble portion in methanol phase (PEEP M ). PEEP M mainly consists of phenols (64.8 %) and arenes (18.9 %). It was conducted to CHC over Ni 10 % @ β / M at 160 °C for 16 h under 5 MPa of an initial hydrogen pressure (IHP) to obtain CHPEEP M . The results indicate that the relative content of cyclanes in CHPEEP M reaches as high as 93.4 %. In Ni 10 % @ β / M , abundant defects, hierarchical porous composite zeolite with strong Lewis acid sites and uniformly dispersed NNPs play crucial roles in removing heteroatoms and hydrogenating aromatic rings (ARs), respectively. Benzyloxybenzene (BOB) is a model compound with a >C-O- bridge bond and ARs, used to study the catalytic activity of Ni 10 % @ β / M . BOB was completely converted into cyclanes at 160 °C for 2 h under 5 MPa IHP. The high yield of polycyclic alkanes is related to the coupling between the active fragments formed after >C-O- cleavage and the main structure. The synergistic transfer of H···H, δ+ H···H δ- , and H + generated by Ni 10 % @ β / M activation of H 2 is key to the hydrogenation of ARs via induced >C-O- bond cleavage, leading to the formation of saturated cyclanes.
✓ 已验证
产品关联
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2024
·
IF 1.7
Yu Yue,Chen Xiaolu,He Ping,Xu Zhiwen,Wu Xiao,Chen Hong,Yang Songlin,Yu Jia,Gao Shuang
A number of Ce 1-x Mn x catalysts with different Mn contents were prepared by resol-assisted cationic coordinative co-assembly approach and used for the synthesis of dimethyl carbonate (DMC) from CO 2 and methanol. Multiple characterizations of XRD, FT-IR, TEM, BET, CO 2 -TPD, NH 3 -TPD, H 2 -TPR, XPS analyses were applied to investigate the surface properties of the Ce 1-x Mn x catalysts. It turned out that adjusting the proper concentration of Mn ions not only increased the pore volumes, but also improved the content of medium acidic and medium basic sites. When a small amount of Mn was added, the presence of Mn 2+ on the catalyst surface enhanced, facilitating the conversion of Ce 4+ to Ce 3+ , and leading to higher oxygen vacancy concentration. Consequently, the adsorption and activation of CO 2 and methanol were promoted, and the catalytic efficiency of the reaction was improved. It was found that Ce 0.95 Mn 0.05 catalyst exhibited the best catalytic activity, achieving a high DMC yield of 6.44 mmol/g (120 °C, 6.5 MPa, 4 h). Graphical Abstract
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Cong He,Xiangjuan Ma,Huajun Feng,Yangcheng Ding,Yijing Xia,Zhiwei Wang
A flow-through peroxymonosulfate (PMS) electro-activation system with a polyacrylonitrile-based carbon fiber (PCF) membrane anode (denoted as E-PCF-PMS system) was developed. The introduction of the PCF membrane anode enabled the flow-through electrocatalytical system to achieve a remarkable tetracycline (TC) removal of 96.0 ± 0.2 % within 15 min, with a degradation rate of 0.273 min −1 . Scavenging investigations revealed that singlet oxygen ( 1 O 2 ) was the dominant reactive oxygen species for TC degradation in the E-PCF-PMS system, and this finding was confirmed by electron paramagnetic resonance tests. Potential degradation pathways of TC were identified according to the detected intermediates and calculations of density functional theory, and a decreasing trend in the toxicity of TC intermediates was discovered. Thanks to the 1 O 2 -dominated pathway, the constructed E-PCF-PMS system could achieve efficient TC degradation under different concentrations of several common anions (Cl − , NO 3 − , HPO 4 2− , and HCO 3 − ) and humic acid (HA). General applicability and reusability tests demonstrated the excellent practicability of the proposed system. The PMS electro-activation system offers a potential technique for high-efficient degradation of contaminants in water and wastewater.
✓ 已验证
产品关联
DOI
高影响因子
MINERALS ENGINEERING
·
2024
·
IF 4.9
Lucheng Zhang,Lu Wang,Mingqing Zhang,Tingting Wang,Gang Kang,Shilong Wu,Yi She
Cyanide has been widely used in gold extraction due to its cost-effectiveness, high selectivity and recovery. Regrettably, its wide application also leads to the presence of a large amount of thiocyanogen (SCN − ) in the tail liquid of mineral processing plants, which affects the quality of the effluent water, and thus poses a threat to the ecological environment and human health. This paper investigates the degradation of high concentration of SCN − in water using electrochemical oxidation/periodate (E-GP/PI) system. A degradation rate of 90.25 % of SCN − was achieved by optimising various operating parameters. The effects of organic matter and typical heavy metal ion concentrations on the degradation of SCN − were investigated, and it was found that Cu 2+ was able to promote the degradation of SCN − through the formation of stable complexes with SCN − , which enhanced the degradation rate to 96.48 %. However, the presence of Octadecyltrimethylammonium bromide (OTAB) and butylxanthin hindered the degradation process, where 500 mg/L of OTAB reduced the degradation rate of SCN − to 80.88 %, while 100 mg/L of butylxanthin reduced the degradation rate to 78.66 %. On this basis, experiments were carried out using real wastewater samples and SCN − degradation efficiencies of about 90 % were obtained. Afterwards, through electron paramagnetic resonance analysis, free radical burst, ion chromatograph and other research techniques, IO 3 and O 2 – were obtained as the main drivers of SCN − degradation and SCN − degradation pathways were elucidated. Finally, the E-GP/PI system was shown to be effective in reducing the ecotoxicity of SCN − by increasing the 24-h LC 50 from 12.5 % to 48.5 % in a toxicity test with daphnia . This study provides a new idea for the green and efficient treatment of SCN − rich beneficiation tail liquid.
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Jingjing Tang,Hongchao Li,Xuan Zhang,Jieshu Qian,Bingcai Pan
Fe-based metal–organic frameworks (MOFs) have garnered significant attention as catalysts for heterogeneous Fenton reactions, while the limited efficiency of the Fe(III)/Fe(II) redox cycle hinders their widespread use in wastewater treatment. Herein, we successfully incorporated carbon nanotubes (CNTs) into MIL-101(Fe) to modulate the coordination environment of Fe for achieving better catalytic activity. The MIL-101(Fe)/CNTs/H 2 O 2 system shows outstanding performance in degrading various pollutants, with the catalytic activity of the MIL-101(Fe)/CNTs composites (98.8%) significantly surpassing that of MIL-101(Fe) alone (26.4%) or CNTs alone (3.5%). Multiple experimental findings suggest that this synergistic effect is primarily attributed to the C-O-Fe bridge bonds resulting from the interaction of surface carboxyl groups on CNTs with Fe in MIL-101(Fe). This unique coordination structure accelerates the redox cycle of Fe(III)/Fe(II), thereby promoting the generation of hydroxyl radicals (HO • ). Furthermore, the MIL-101(Fe)/CNTs composites demonstrate excellent reusability and stability, maintaining effectiveness over a wide pH range from 3.0 to 6.5. This study provides new insights into regulating the microstructure of Fe-based MOFs to enhance their Fenton catalytic activity.
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Chuanyu Chen,Simeng Xia,Fan Chen,Ting Peng,Lin Deng,Huiying Wu,Zhou Shi
The Fe(II)/peracetic acid (PAA) process shows significant potential for the removal of organic pollutants due to the rapid reaction between Fe(II) and PAA. However, the slow reduction from Fe(III) to Fe(II) leads to the continuous or excess dosing of Fe(II) during practical application. In this study, epigallocatechin gallate (EGCG), a typical reagent extracted from green tea, was used to enhance the degradation of coumarin (COU) by Fe(II)/PAA for the first time. A complete elimination of COU (25 μM) was achieved in the presence of 50 μM Fe(II), 300 μM PAA, and 25 μM EGCG, exhibiting a k obs value of 0.108 min −1 , which was 27 times higher than that observed with Fe(II)/PAA (0.004 min −1 ). Further, Fe(II)/EGCG/PAA demonstrated remarkable pH tolerance, with a COU removal efficiency exceeding 80 % across a pH range of 3–9. Mechanisms investigations revealed that •OH played a dominant role in COU degradation by Fe(II)/EGCG/PAA (accounting for 98.2 %). The increase in EGCG concentration from 10 to 100 μM resulted in a decreased formation of •OH yield and an enhanced generation of RO•. These findings highlight the capability of EGCG to improve the oxidation capacity of Fe(II)/PAA and modulate reactive species formation. The outstanding oxidation capacity and environmental friendliness of Fe(II)/EGCG/PAA process render it a potential strategy to eliminate organic pollutants in actual water treatment.
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Jun Zhang,Shuyue Liu,Shiyu Lu,Chunyuan Wang,Pingjuan Liang,Huan Yi,Mengjie Li,Laizheng Luo,Rong Wang,Guangming Jiang
Improving the utilization of hydrogen radicals (H*) is of great significance for effective Pd-mediated electrocatalytic hydrodechlorination (EHDC) in detoxifying chlorinated organic pollutants (COPs). However, the limited H* utilization by single Pd arises from its inadequate performance in adsorbing/activating COPs and inferior mass transfer of low-concentration COPs. In this study, an urchin-like yolk/shell TiO 2 spheres with mesoporous structure are developed for supporting Pd nanoparticles (Pd/U-TiO 2 ), which exhibits superior EHDC activity and selectivity for 2,4-DCP reduction. Notably, the prepared Pd/U-TiO 2 catalyst achieves a mass activity of 4.2 min −1 g Pd -1 and a specific activity of 1.94 min −1 mol Pd -1 when detoxifying 50 mg/L of 2,4-DCP at −0.85 V, surpassing the most reported catalysts. Furthermore, the Pd/U-TiO 2 catalyst consistently demonstrates higher H* utilization efficiency compared to single Pd, regardless of the 2,4-DCP concentration or reaction mode (batch or continuous-flow). This enhanced H* utilization efficiency is attributed to two key factors: the urchin-like and yolk/shell structure of U-TiO 2 enhances the mass diffusion of 2,4-DCP, and the strong interactions between Pd and U-TiO 2 generate electron-rich Pd species that enhance the adsorption and activation of COPs. Overall, this work highlights the synergistic effects of strong metal-support interactions and mass diffusion in enhancing atomic H* utilization. This study lays a significant experimental and theoretical foundation for designing efficient electrocatalysts for the detoxification of chlorinated organic pollutants and various other halogenated organic pollutants.
✓ 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）