Science Advances
·
2020
·Vol. 6
·期 45
·
IF 13.117
Jiang Yan,Qinglei Meng,Xiaojun Shen,Bingfeng Chen,Yang Sun,Junfeng Xiang,Huizhen Liu,Buxing Han
Phenol is an important commodity chemical in the industry, which is currently produced using fossil feedstocks. Here, we report a strategy to produce phenol from lignin by directly deconstructing C sp2 –C sp3 and C–O bonds under mild conditions. It was found that zeolite catalyst could efficiently catalyze both the direct C sp2 –C sp3 bond breakage to remove propyl structure and aliphatic β carbon–oxygen (C β– O) bond hydrolysis to form OH group on the aromatic ring. The yield of phenol could reach 10.9 weight % with a selectivity of 91.8%. In this unique route, water was the only reactant besides lignin. A scale-up experiment showed that 4.1 g of pure phenol could be obtained from 50.0 g of lignin. The reaction pathway was proposed by a combination of control experiments and density functional theory studies. This work opens the way for producing phenol from lignin by direct transformation of C sp2 –C sp3 and C–O bonds in lignin.
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DOI
高影响因子
ENERGY & FUELS
·
2023
·
IF 5.3
Liuyi Hu,Zhihang Lu,Fei Chen,Jun Zhang,Yang Xia,Wenkui Zhang,Yongping Gan,Xinping He,Wenlong Song,Hui Huang
Attributed to high theoretical capacity and abundant reserves, Si/C anodes have been commercialized in lithium-ion batteries (LIBs). However, the shortcomings of poor interfacial compatibility, low rate performance, and bad stability remain to be overcome. In this paper, a facile method for the synthesis of silicon/iron oxide/carbon (Si/Fe3O4/C) composites by ball-milling in a supercritical carbon dioxide (scCO2) fluid medium is proposed. This method utilizes the diffusion characteristics, extremely low viscosity, and excellent mass transfer properties of supercritical fluids. Under the infiltration of an scCO2 fluid, mesophase carbon microspheres (MCMB) are exfoliated into graphite flakes and achieve good interfacial fusion with silicon and Prussian blue during ball-milling. The Prussian blue is transformed into Fe3O4 by subsequent heat treatment under a nitrogen atmosphere, and Fe3O4 introduced in this way enhances the lithium-storage capacity, cycling stability, and rate performance significantly of Si/C anodes. As an anode for LIBs, the reversible capacity of Si/Fe3O4/C reaches 1363 mA h g–1 after 600 cycles at 1 A g–1. This study provides an idea for the design and fabrication of Si-based anode materials with high capacity and long cycle life.
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高影响因子
International Journal of Applied Ceramic Technology
·
2024
·Vol. 22
·期 1
·e14889
·
IF 1.8
Haopeng Cai,Kun Jiang,Lihua Gao,Yinglong Wei
In this paper, we prepared Al 2 O 3 –ZrO 2 –SiB 6 composite ceramics with excellent performance by introducing the second-phase high-strength healing agent SiB 6 in zirconia-toughened alumina system, artificially created cracks using Vickers hardness tester, investigated the effects of heat treatment temperature (600–1200°C) and time (0–300 min) on the microscopic morphology and bending strength of the ceramics, revealed the healing mechanism, and studied the oxidation resistance properties. It was found that the healing effect was better at heat treatment of 90 min at 700°C and 60 min at 800°C, and the flexural strength was restored to more than 95% of that of the smooth specimens in both cases. Crack repair was mainly achieved by the reaction of SiB 6 , ZrB 2 , and B 4 C with O 2 . Below 800°C, healing was mainly achieved by the reaction of SiB 6 and B 4 C with O 2 , and the generated B 2 O 3 and SiO 2 migrated toward the crack to repair it. When the healing temperature is higher than 800°C, ZrB 2 also reacts with oxygen to produce B 2 O 3 and t-ZrO 2 . It was found that the oxidation weight gain per unit area of the Al 2 O 3 –ZrO 2 –SiB 6 ceramic composite at different temperatures was small, and it has excellent oxidation resistance.
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高影响因子
CATALYSIS LETTERS
·
2024
·Vol. 154
·期 7
·3426-3440
·
IF 2.3
Han Qi,Shi Yong,Han Yuchan,Chen Rui,Hou Yuelei,Li Jun
A series of niobium-based catalysts with carboxylated multi-walled carbon nanotube (C-CNT) as support were prepared by modified wet-chemical technique under ultrasonication. Three types of catalysts with active component niobium attached only on the inner or outer walls respectively, or mainly on the outer walls were obtained by adjusting the impregnation strategies. The catalysts were characterized systematically by SEM, TEM, XRD, Raman, FT-IR, XPS, and N 2 adsorption–desorption. It was found that niobia species was highly dispersed on the outer wall or the channels of C-CNT. There are abundant oxygen-containing groups on the catalysts. Strong chemical interactions between the support and Nb 2 O 5 are evident. The catalytic performances of the C-CNT-supported catalysts were evaluated for the selective oxidation of cyclopentene (CPE) to glutaraldehyde (GA) with 30 wt% aqueous H 2 O 2 as oxidant. The conversion of CPE and the selectivity to GA reached 98.3% and 59.3% respectively under the optimized conditions. No significant deterioration of the catalytic performance was found in the catalyst-cycling experiments, indicating the stability of the catalyst. Hot filtration experiments revealed that the catalytic reaction was heterogeneous. The good performance of the catalyst in ethanol makes the catalytic system of an excellent application prospect. Graphical
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高影响因子
Materials Chemistry Frontiers
·
2021
·Vol. 5
·期 6
·2783-2790
·
IF 6.482
Guangyuan Du,Mengli Tao,Yuruo Qi,Wei Gao,Shu-juan Bao,Maowen Xu
A sustainable and non-toxic polyanionic cathode material is an ideal choice for high-performance eco-friendly sodium-ion batteries (SIBs), but most of the polyanionic cathode materials contain vanadium/chromium or other toxic atoms. Based on Fe atoms, pyrophosphate polyanionic Na7Fe4.5(P2O7)4 is a promising candidate to meet the sustainable, non-toxic and cost-effective requirements. However, its inferior rate capability hinders its further application. Besides, employing quasi-solid-state polymer electrolytes (QSPEs) is an advisable strategy to mitigate the shortcomings of traditional SIBs caused by liquid electrolytes. In light of this, a high-rate carbon-coated Na7Fe4.5(P2O7)4@C (NFPO@C) cathode and a quasi-solid-state polymer electrolyte membrane (PFSA-Na) with high ionic conductivity are provided in this work. Quasi-solid-state full cells based on the NFPO@C cathode, the PFSA-Na membrane and the hard carbon anode can enable high-rate performances and extremely stable cycle life at 20C with a capacity decay of 0.0057% per cycle for 2000 cycles. The NFPO@C cathode material, PFSA-Na membrane and full cells demonstrated here could pave the way for high-rate quasi-solid-state sodium-ion batteries for practical application.
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高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Guiyan Sun,Shaobo Lai,Xiangbang Kong,Zhiqiang Chen,Kun Li,Rong Zhou,Jing Wang,Jinbao Zhao
A blend cathode has been prepared by mixing both LiNi0.5Co0.2Mn0.3O2 (NCM523) of high energy density and high specific capacity and LiFe0.15Mn0.85PO4/C (LFMP/C) of excellent thermal stability via a low-speed ball-milling method. The lithium ion batteries using the blend cathode with LFMP/C of optimum percent exhibit better capacity retention after 100 cycles than those using only single NCM523 or LFMP/C. Both theoretical simulation and experimental rate performances demonstrate that the electrochemical property of blend cathode materials is predictable and economical. In addition, the thermal behaviors of blend cathodes are studied by using differential scanning calorimetry analysis. The thermal stability of blend cathode materials behaves better than that of the bare NCM523 accompanied with an electrolyte. It is found that the outstanding rate and thermal performance of the blend cathode is due to the prominent synergistic effect between NCM523 and LFMP/C, and 10% LFMP/C in the blend cathode materials is the most adaptable as considering both electrochemical and thermal properties simultaneously.
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高影响因子
IONICS
·
2018
·Vol. 24
·期 11
·3691-3698
·
IF 2.347
Wang Jianping,Zhang Lan,Zhang Haitao
Additives play critical roles on the performances of electrolytes. Vinyl tris(2-methoxyethoxy) silane (VTMS) was utilized as additive in the ethylene carbonate (EC)/ethyl methyl carbonate (EMC) electrolyte. Scanning electron microscopy (SEM) was used to examine the morphological evolution of electrodes after cycling. The morphology of the SEI film for Si/C electrode was observed by transmission electron microscopy (TEM). X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectra (EIS) techniques were employed to understand the effect of electrolytes containing VTMS on the formation of the SEI layer. Our experiments reveal that the capacity and cyclability of Si/C anode are improved due to formation of a stable SEI on the anode surface. These behaviors are confirmed by constant current charge–discharge and electrochemical impedance spectra (EIS) study. In particular, 5 wt.% VTMS in EC:DEC (3:7 wt.%) shows the most optimal reversible capacity and best cycle stability. Such a performance can be attributed to the formation of a more flexible SEI containing Li 2 CO 3 , LiF, and organosilicone compounds, which can reduce further reduction of electrolyte.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2023
·Vol. 58
·期 33
·13373-13386
·
IF 4.5
Shi Chonghua,Liu Xinyu,Fu Hang,Wang Jing,Yao Shaowei
As one of the most promising high-capacity anode materials for lithium-ion batteries, Sn-based anode materials have the advantages of high capacity (994 mAh g −1 ) and low price. But the anode material has large volume expansion during the cycle process, resulting in battery capacity attenuation. Therefore, carbon wrapping is used to alleviate this problem. In this work, SnO 2 nanoparticles are coated by electrospinning technology, and microspherical Sn@C composite materials are obtained after further heat treatment. The results show that when the content of SnO 2 nanoparticles is 0.13 g, the obtained Sn@C microsphere electrode material still has a high reversible discharge specific capacity of 616.90 mAh g −1 after 100 cycles at a current density of 100 mA g −1 . When the current density is 500 mA g −1 , the specific capacity is still as high as 558.20 mAh g −1 after 500 cycles, and the Sn@C microsphere electrode material exhibits excellent electrochemical performance. This provides an idea for developing high performance anode materials for lithium-ion batteries.
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高影响因子
IONICS
·
2016
·Vol. 23
·期 3
·575-583
·
IF 2.119
He Zhangxing,Jiang Yifan,Sun Dan,Dai Lei,Wang Haiyan
Inferior rate capability is a big challenge for LiTi 2 (PO 4 ) 3 anode for aqueous lithium-ion batteries. Herein, to address such issue, we synthesized a high-performance LiTi 2 (PO 4 ) 3 /carbon/carbon nanotube (LTP/C/CNT) composite by virtue of high-quality carbon coating and incorporation of good conductive network. The as-prepared LTP/C/CNT composite exhibits excellent rate performance with discharge capacity of 80.1 and 59.1 mAh g −1 at 10 C and 20 C (based on the mass of anode, 1 C = 150 mA g −1 ), much larger than that of the LTP/C composite (53.4 mAh g −1 at 10 C, and 31.7 mAh g −1 at 20 C). LTP/C/CNT also demonstrates outstanding cycling stability with capacity retention of 83.3 % after 1000 cycles at 5 C, superior to LTP/C without incorporation of CNTs (60.1 %). As verified, the excellent electrochemical performance of the LTP/C/CNT composite is attributed to the enhanced electrical conductivity, rapid charge transfer, and Li-ion diffusion because of the incorporation of CNTs.
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高影响因子
ELECTROCHIMICA ACTA
·
2012
·
IF 3.832
Xiaolei Sun,Xinghui Wang,Li Qiao,Duokai Hu,Na Feng,Xiuwan Li,Yingqi Liu,Deyan He
Porous SnO 2 –Sn/C composites have been synthesized via directly pyrolysis of mixtures of SnO 2 powder and poly(vinylidene fluoride) without any surfactant addition and other treatment. The composites are composed of SnO 2 and Sn nanoparticles which are well encapsulated in porous carbon matrix as characterized by transmission electron microscopy, X-ray powder diffraction and micro-Raman spectrometer. The obtained materials were used as anode for lithium ion batteries, a discharge capacity of 1171 mAh g −1 and a charge capacity of 611 mAh g −1 were shown in the first cycle at a current density of 100 mA g −1 , and good cycling performance achieved even at current density as high as 800 mA g −1 . The good electrochemical behaviors could be attributed to the formation of Sn nanoparticles which can increase the reversible capacity and the porous carbon matrix which is of excellent buffering effect and high electronic conductivity.
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高影响因子
SENSORS AND ACTUATORS A-PHYSICAL
·
2024
·
IF 4.1
Muzhi Li,Xiaofeng Zhao,Yingzheng Liu,Di Peng,Weiwei Cai,Hong Liu
Phosphor thermometry has demonstrated significant potential for nondestructive high-temperature measurements in gas turbines . To expand the measurement range through lifetime-based phosphor thermometry, we developed a novel phosphor, YAG:Dy co-doped with Tb (YAG:Dy,Tb). Three YAG:Dy,Tb samples with varying Tb concentrations were synthesized through the sol–gel method. A fiber-optic-coupled measurement system was established to capture multiple emission peaks of YAG co-doped with Dy 3+ and Tb 3+ at 544 nm, 484 nm, and 458 nm. Efficient energy transfer from Dy 3+ to Tb 3+ resulted in a substantial enhancement of Tb 3+ emission at 544 nm under 355 nm excitation. Owing to the energy transfer, the temperature measurement range under the lifetime method was extended from room temperature to 1600 °C using the combination of Tb 3+ emission at 544 nm and Dy 3+ emission at 458 nm. YAG:Dy,Tb samples with higher concentrations of Tb 3+ exhibited superior temperature measurement performance, mainly owing to their stronger signal-to-noise ratio at >1000 °C. The performances of different emission peaks were also compared according to temperature uncertainty, which generally ranged from 0.1 °C to 2.7 °C across the entire measurement range.
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高影响因子
ChemElectroChem
·
2021
·Vol. 8
·期 23
·4550-4558
·
IF 4.59
Yanyang Guo,Xianyang Li,Zhuqing Zhao,Hongya Wang,Jiakang Qu,Zuojun Hu,Hongwei Xie,Huayi Yin
Conventional sulfide metallurgy suffers from SO x gas emission and high energy consumption, owing to the multiple-step extraction processes and high temperatures that are above the melting point of the extracted metals. Herein, liquid Cu 2 Sb alloy can be directly electrochemically extracted from the liquid Sb 2 S 3 -Cu 2 S with no sulfide oxides emission in eutectic NaCl-KCl molten electrolyte at 730 °C. The use of Sb 2 S 3 decreases the melting point of Cu 2 S and the Sb decreases the melting temperature of Cu. The Sb 2 S 3 -Cu 2 S mixture experiences three stages in the electrochemical desulfurization process: the insertion of Na + into liquid sulfides, the removal of S 2− and metallization, and finally the formation of uniform liquid Cu 2 Sb alloy. The Sb 2 S 3 -Cu 2 S can be completely electro-converted into Cu 2 Sb at 2.6 V for 6 hours. This study provides a straightforward and environmentally friendly route to electro-synthesize liquid alloys from their molten sulfide minerals. Graphical Paving the way : The conventional pyrometallurgical route extracts copper and antimony metals from their sulfide minerals through roasting, smelting, and refining processes. These steps call for high temperature and generate SO 2 and CO 2 , which will cause intense energy consumptions and pollution. This paper paves a green electrochemical route to prepare liquid Cu 2 Sb alloy from their molten sulfides at 730 °C without SO x (CO 2 ) emissions.
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高影响因子
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