ChemSusChem
·
2018
·Vol. 11
·期 22
·3965-3974
·
IF 7.411
Hai Wang,Liang Wang,Jian Zhang,Chengtao Wang,Ziyu Liu,Xinhua Gao,Xiangju Meng,Seung Jo Yoo,Jin-Gyu Kim,Wei Zhang,Feng-Shou Xiao
Graphical Ready layer one : A newly synthesized catalyst with layered cobalt oxide on the surface of titania (layer-CoO x /TiO 2 ) is highly selective towards the aerobic oxidation of C−H bonds in a series of hydrocarbons. In-depth structural and functional characterization reveal that the layer-CoO x /TiO 2 readily reacts with O 2 for the adsorption and activation of C−H bonds. Construction of efficient interfaces to improve the performance of supported metal catalysts is a challenging but effective technique. A newly synthesized catalyst with layered cobalt oxide on the surface of titania (layer-CoO x /TiO 2 ) is highly selective towards the aerobic oxidation of C−H bonds in a series of hydrocarbons under sustainable conditions. The layer-CoO x /TiO 2 easily outperforms the state-of-the-art noble metal catalysts and homogeneous cobalt salts used in industry. In-depth structural and functional characterization reveal that the layer-CoO x /TiO 2 readily reacts with O 2 for the adsorption and activation of C−H bonds. The layered structure of CoO x can maximize the interfacial effect of CoO x /TiO 2 leading to a good performance for the oxidation of C−H bonds.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
POLYMER COMPOSITES
·
2022
·Vol. 43
·期 9
·6505-6520
·
IF 3.531
Zhaorong Zhu,Yu Liu,Yaseen Muhammad,Ruinan Pei,Yingyun Li,Jing Li
Electrospinning is used to control the interface structure of macro-polyacrylonitrile (PAN) fibers, and nano-porous fibers (E-PAN) which possess enhanced adhesion and interface effects. Herein, E-PAN was prepared via electrospinning and was in turn incorporated into styrene-butadiene-styrene (SBS) asphalt to prepare PAN modified asphalt. The effect of E-PAN addition on the performance of modified asphalt was explored. Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction, scanning electron microscopy, atomic force microscopy (AFM), and AFM tests confirmed that E-PAN exhibited a highly rough nano-porous skeleton without any prominent structural damage during the preparation process. The three major indexes, dynamic shearing rheometer, MSCR, rotational viscosity, and thermogravimetric analysis tests results showed that E-PAN modified asphalt exhibited excellent viscoelasticity, anti-rutting and anti-fatigue properties and thermal stability (T HRI of 192.7°C). FT-IR test of the four components of modified asphalt confirmed that E-PAN chemically crosslinked with the saturates and aromatics in the base asphalt and SBS, which resulted in a uniform and well-developed network structure. In addition, Brauner-Emmett-Teller and fluorescence microscopy results confirmed that E-PAN got fully swollen in a behavior similar to that of SBS in the base asphalt, and hence helped SBS to form an excellent network structure in asphalt. E-PAN played the important role of stress buffer, mutual entanglement, and good thermal insulation inside the asphalt.
研究领域:
材料科学
·
土木工程
·
化学工程
✓ 已验证
DOI
高影响因子
SOLID STATE IONICS
·
2017
·
IF 2.354
Leyu Zhan,Yao Zhang,Xiangyang Zhuang,Hui Fang,Yunfeng Zhu,Xinli Guo,Jian Chen,Zengmei Wang,Liquan Li
The x LiBH 4 -Li 3 N ( x = 1, 2, 4) composites were investigated on their lithium ionic conductivities . They maintained the original phase structures of orthorhombic LiBH 4 and hexagonal β-Li 3 N during ball milling according to the analyses by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Electrochemical impedance spectra (EIS) tests showed that LiBH 4 -Li 3 N composites lift the lithium ionic conductivities from that of bulk LiBH 4 by nearly 100 times at low temperature. LiBH 4 -Li 3 N offers 1.06 × 10 − 5 S cm − 1 of conductivity while bulk LiBH 4 possesses only 2.05 × 10 − 7 S cm − 1 at 323 K. Cyclic voltammetry (CV) tests indicated that the voltage window of composites could attain 3 V, which is much more stable than Li 3 N (< 1 V). No thermodynamic incident appears in DSC curves except for the orthorhombic-hexagonal transition endothermic peak of LiBH 4 in the x LiBH 4 -Li 3 N composites. It confirms the phases stabilities of the x LiBH 4 -Li 3 N ( x = 1, 2, 4) composites before and after CV tests. In-situ solid state Nuclear Magnetic Resonance (NMR) tests on LiBH 4 -Li 3 N illustrated that the high conductivity in low temperature should not come from high-temperature phase of LiBH 4 . Therefore, the enhancement of lithium ionic mobility of the composite might be attributed to both Li 3 N and the interfaces between small crystallites where transmission electron microscope (TEM) morphology showed the appearance of amorphous grain boundary.
研究领域:
材料科学
·
固态离子学
·
能源化学
·
电化学
·
纳米材料
·
固体电解质
·
锂离子电池
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·Vol. 51
·期 5
·6587-6598
·
IF 5.1
Bo Li,Yigao Chen,Shaopeng Wang
A (ZrC/SiC) 35 multilayer alternating coating with 500∼700 nm sublayers thickness and 70 interfaces was deposited on sharp leading edge C/C composites by continuous CVD method. Its mechanical property and ablation resistance were assessed by scratch test and oxy-acetylene flame respectively and compared with ZrC monolayered coating. The (ZrC/SiC) 35 multilayer alternating coating exhibited a high bonding strength via the regulation of sub-micro alternating stress field and the inhibition of crack propagation by 70 interfaces, showing a high critical load L C3 of 22.521 N, which was higher than that of ZrC monolayered coating of 5.688 N. Furthermore, the coating revealed excellent ablation resistance evidenced by its intact oxide layer, and the mass and linear ablation rates were only 0.17 mg/s and 0.87 μm/s respectively. The layer-by-layer oxidation behavior allowed the advantages of ZrC and SiC sublayers to be fully utilized, thus maintaining the layered oxide structure. Furthermore, the total 35 layers of thin ZrO 2 layers improved the fault tolerance ability of coating in harsh ablative environments.
研究领域:
材料科学
·
表面工程
·
高温防护涂层
·
复合材料
·
力学性能
·
热防护系统
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）