SOLID STATE IONICS
·
2017
·
IF 2.354
Yan Sun,Wenning Yan,Li An,Bingbin Wu,Kaifu Zhong,Ruizhi Yang
A super solid electrolyte of Ba-substituted Li 10 GeP 2 S 12 is designed and fabricated to achieve high electrochemical stability. Among the Ba-substituted Li 10 GeP 2 S 12 solid electrolytes, the composition of Li 9.4 Ba 0.3 GeP 2 S 12 exhibits the highest ionic conductivity of 7.04 × 10 − 4 S cm − 1 with an activation energy of 28.27 kJ mol − 1 at 25 °C. The electrochemical window of Li 9.4 Ba 0.3 GeP 2 S 12 is between 0 and 6 V (vs. Li), which is higher than the typical 5 V window of Li 10 GeP 2 S 12 . As compared with Li 10 GeP 2 S 12 , Li 9.4 Ba 0.3 GeP 2 S 12 demonstrates a significantly reduced polarization and a better cycle stability though its ionic conductivity is slightly lower than that of the former. The electrochemical stability of Ba-substituted Li 10 GeP 2 S 12 can be attributed to the structural stability resulting from the stable interaction between Ba 2 + and S 2 − in the structure.
研究领域:
材料科学
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固态离子学
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电化学
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能源材料
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无机固体化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMISTRY
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2013
·Vol. 31
·期 3
·371-376
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IF 0.917
Wei Zhu,Haoyang Wang,Haihui Peng,Guosheng Liu,Yinlong Guo
Pd-catalyzed oxidative coupling reaction was of great importance in the aromatic C H activation and the formation of new C O and C C bonds. Sanford has pioneered practical, directed C H activation reactions employing Pd(OAc) 2 as catalyst since 2004. However, until now, the speculated reactive Pd(IV) transient intermediates in these reactions have not been isolated or directly detected from reaction solution. Electrospray ionization tandem mass spectrometry (ESI-MS/MS) was used to intercept and characterize the reactive Pd(IV) transient intermediates in the solutions of Pd(OAc) 2 -catalyzed oxidative coupling reactions. In this study, the Pd(IV) transient intermediates were detected from the solution of Pd(OAc) 2 -catalyzed oxidative coupling reactions by ESI-MS and the MS/MS of the intercepted Pd(IV) transient intermediate in reaction system was the same with the synthesized authentic Pd(IV) complex. Our ESI-MS(/MS) studies confirmed the presence of Pd(IV) reaction transient intermediates. Most interestingly, the MS/MS of Pd(IV) transient intermediates showed the reductive elimination reactivity to Pd(II) complexes with new C O bond formation into product in gas phase, which was consistent with the proposed reactivity of the Pd(IV) transient intermediates in solution.
研究领域:
有机化学
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金属有机化学
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分析化学
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催化化学
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质谱学
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2017
·Vol. 28
·期 11
·1438-1447
·
IF 1.907
Xin Liu,Xuewen Guo,Yunfei Zhi,Shaoyun Shan,Yonghao Ni,Qingming Jia
The recent development of sulfur dioxide (SO 2 ) polymerization has seen a renaissance in its chemistry, especially poly(olefin sulfone)s from the copolymerization of SO 2 , and unsaturated hydrocarbons can be found to have many applications, including transient electronic packaging, drug delivery, and electron beam-resistant materials. In this work, a type of functional poly(norbornene sulfone) was synthesized via two different polymerization methods. Aiming to understanding the effects of different polymerization methods on poly(olefin sulfone)s and gain further understanding on the kinetics of poly(olefin sulfone)s's thermal instability, we investigated their detailed thermal degradation behaviors using thermogravimetry and analyzed the resultant kinetics in accordance with three kinetic models. The results supported the conclusion that although the poly(norbornene sulfone)s obtained have different activation energy, the thermal degradation kinetics are the same and also obey the D n type. Copyright © 2017 John Wiley & Sons, Ltd.
研究领域:
高分子化学
·
材料科学
·
热分析
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功能高分子
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可控降解材料
✓ 已验证
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2020
·
IF 7.539
Kaijun Wang,Sining Yun,Tian Xing,Bingjie Li,Yasir Abbas,Xinming Liu
The effects of binary and ternary trace elements (TEs) (Fe/Co, Fe/Ni, and Fe/Co/Ni) on the anaerobic digestion (AD) of cattle manure were investigated using kinetic models (first-order, logistic, modified Gompertz, and Coats-Redfern) and experimental measurements. Binary and ternary TEs can significantly improve the biogas production rate and yield potential. The deviation between the predicted and measured data for biogas yield with logistic model (2.1%–5.3%) and modified Gompertz model (0.32%–2.9%) was smaller than that with first-order kinetic model (6.9%–9.9%). The Coats-Redfern model fitting indicated that the activation energy of digestates with trace elements during pyrolysis was reduced by 3.9%–26.2% compared with the control group. Meanwhile, digestates with TEs showed remarkable fertility (5.72%–5.95%). The combination of kinetic models and experimental measurements can effectively quantify the effect of TEs on AD performance and provide an informed choice for industrial production.
研究领域:
环境科学
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农业工程
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生物质能源
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废物资源化
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生物化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
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2017
·
IF 6.395
Xiubo Xie,Ming Chen,Peng Liu,Jiaxiang Shang,Tong Liu
Nickel sulfides decorated reduced graphene oxide (rGO) has been produced by co-reducing Ni 2+ and graphene oxide (GO), and is subsequently ball milled with Mg nanoparticles (NPs) produced by hydrogen plasma metal reaction (HPMR). The nickel sulfides of about 800 nm completely in situ change to MgS, Mg 2 Ni and Ni multiple catalysts after first hydrogenation/dehydrogenation process at 673 K. The Mg-5wt%NiS/rGO nanocomposite shows the highest hydrogen desorption kinetics and capacity properties, and the catalytic effect order of the additives is NiS/rGO, NiS and rGO. At 573 K, the Mg-NiS/rGO nanocomposite can quickly desorb 3.7 wt% H 2 in 10 min and 4.5 wt% H 2 in 60 min. The apparent hydrogen absorption and desorption activation energies of the Mg-5wt%NiS/rGO nanocomposite are decreased to 44.47 and 63.02 kJ mol −1 , smaller than those of the Mg-5wt%rGO and Mg-5wt%NiS samples. The best hydrogen desorption properties of the Mg-5wt%NiS/rGO nanocomposite can be explained by the synergistic catalytic effects of the highly dispersed MgS, Mg 2 Ni and Ni catalysts on the rGO sheets, and the more nucleation sites between the catalysts, rGO sheets and Mg matrix.
研究领域:
材料科学
·
纳米科技
·
能源化学
·
催化化学
·
储氢材料
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2013
·
IF 4.093
Qiang Xu,Yang Yang,Jie Yang,Xiaozu Wang,Zhaohui Wang,Yong Wang
Conformal and smooth TiO 2 thin layers were coated on the surface of porous PTFE membranes subjected to a plasma activation process by atomic layer deposition (ALD). In contrast, TiO 2 was deposited on the PTFE surface as globular particulates without plasma activation due to the inert chemical nature of PTFE surface. X-ray photoelectron spectrometry confirmed the formation of functional groups on the plasma-activated PTFE surface which served as active sites for the homogeneous adsorption and reaction of ALD precursors. Scanning and transmission electron microscopy revealed the uniformity of the deposited layer and the precise control of its thickness by changing ALD cycle numbers. The water contact angle measurement showed that the hydrophobic surface gradually turned to be near superhydrophilic with the increment of ALD numbers. Also, the membrane mean pore size was progressively reduced by simply altering the ALD numbers. At proper deposition conditions , the modified membranes gained an increase of pure water flux of more than 150% and simultaneously a doubled retention compared to the original unmodified membrane. This research provides an efficient approach devoid of any harsh treatments to modifying PTFE membranes for achieving specific functions, which also can be applied to other organic materials especially with chemical inert surface.
研究领域:
材料科学
·
膜科学与技术
·
表面工程
·
高分子化学
·
环境工程
·
纳米科技
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2013
·Vol. 1
·期 13
·4228-4235
·
IF 0
Yu Bai,Ran Long,Chengming Wang,Ming Gong,Yanrui Li,Hao Huang,Hui Xu,Zhengquan Li,Mingsen Deng,Yujie Xiong
A method has been developed for controlled epitaxial growth on cubic nanocrystals by selectively activating their surface via etching. For example, it produces Pd concave nanocubes via seeding growth on their corners and edges, and in turn, formulates highly active sites for catalysis. This method offers a better capability of preventing atomic addition on undesired locations and maintaining particle size in the seeding process, as compared with the previous technique. With the particle size well maintained, the products fully exhibit superior electrocatalytic performance enabled by active sites and high-index facets in formic acid oxidation. Another contribution of this work is to enable the growth of a noble metal with high catalytic activities on another type of cheaper metal, which greatly reduces the usage of expensive materials while retaining high catalytic activity. In this article, we have demonstrated the deposition of a very limited amount of Pt (only 3.3 wt%) on Pd nanocrystals towards high electrocatalytic activities in an oxygen reduction reaction. Preliminary studies demonstrate that the synthetic strategy can be also applied to the controllable deposition of a different material on the faces of a nanocrystal by simply altering surface conditions.
研究领域:
材料化学
·
纳米科学与技术
·
催化化学
·
电化学
·
表面科学
·
功能纳米材料
✓ 已验证
DOI
危险品化学品经营许可证（带存储）