JOURNAL OF CATALYSIS
·
2020
·
IF 7.888
Jian Zhang,Yazhe Zhang,Jieqiong Zhao,Zhe An,Yanru Zhu,Xin Shu,Hongyan Song,Xu Xiang,Xiaodan Ma,Jing He
Oxidative carbonylation has attracted broad interest from both academia and industry in recent years. Oxycarbonylation of ethanol to diethyl carbonate (DEC) has been of great challenge due to the difficulty in the simultaneous activation of ethanol and CO. This work reports a heterogeneous Cu-Pd pair catalysis for simultaneous activation of ethanol and CO, affording a selectivity of 85.4% to DEC and a space–time yield (STY) of up to 207 mg∙g −1 ∙h −1 . Well distributed Cu-Pd pair affords more Cu (I) sites, promoting CO activation and the followed insertion to adsorbed ethanol. Further increasing ratio of Cu (I) species via the pre-treatment of catalyst with CO and ethanol promotes simultaneously the activation of ethanol and CO, affording a STY of 325 mg∙g −1 ∙h −1 of DEC.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
Materials Reports: Energy
·
2022
·
IF 0
Zhanyou Xu,Yi Xie,Ying Wang
Electrochemical CO 2 reduction reaction (CO 2 RR) exhibits remarkable potential in producing valuable chemicals with renewable energy. Operating CO 2 RR in acidic media is beneficial to solve the issue of low carbon utilization brought by (bi)carbonate formation at the cathode. Suppressing the competing hydrogen evolution reaction and achieving stable CO 2 RR performance remains challenging. Herein, we constructed a 3-dimensional Cu (3D-Cu) gas diffusion electrode (GDE) to achieve efficient C 2 H 4 production with a partial current density ( j C2H4 ) of over 470 mA cm −2 and a Faradaic efficiency (FE C2H4 ) of 40%. With pause electrolysis, the decay rate of the j C2H4 is only half that of the traditional constant electrolysis. The GDE after constant electrolysis was found to suffer from severe salt formation, leading to the decreased activity and poor stability.
研究领域:
电化学
·
材料科学
·
能源化学
✓ 已验证
DOI
Nature Communications
·
2021
·Vol. 12
·期 1
·1-10
·
IF 14.919
Yu Jiafeng,Sun Xingtao,Tong Xin,Zhang Jixin,Li Jie,Li Shiyan,Liu Yuefeng,Tsubaki Noritatsu,Abe Takayuki,Sun Jian
The rational design of high-temperature endurable Cu-based catalysts is a long-sought goal since they are suffering from significant sintering. Establishing a barrier on the metal surface by the classical strong metal-support interaction (SMSI) is supposed to be an efficient way for immobilizing nanoparticles. However, Cu particles were regarded as impossible to form classical SMSI before irreversible sintering. Herein, we fabricate the SMSI between sputtering reconstructed Cu and flame-made LaTiO 2 support at a mild reduction temperature, exhibiting an ultra-stable performance for more than 500 h at 600 °C. The sintering of Cu nanoparticles is effectively suppressed even at as high as 800 °C. The critical factors to success are reconstructing the electronic structure of Cu atoms in parallel with enhancing the support reducibility, which makes them adjustable by sputtering power or decorated supports. This strategy will extremely broaden the applications of Cu-based catalysts at more severe conditions and shed light on establishing SMSI on other metals.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2021
·
IF 3.498
Sai-Li Zheng,Yonghe He,Xiao-Kang Qiu,Yuan-Hui Zhong,Lai-Hon Chung,Wei-Ming Liao,Jun He
A novel metal-organic framework [CuCN(TMBP)·H 2 O] n ( TCuCN ) has been synthesized by the reaction of 3,3′,5,5′-tetramethyl-4,4′-bipyrazole (TMBP) and CuCN. Its structure was determined by single-crystal X-ray diffraction (SCXRD) analysis and further characterized by power X-ray diffraction (PXRD) analysis, FT-IR spectroscopy and thermogravimetric (TG) analysis. Previously reported structurally analogous TCuCl , TCuBr , TCuI have also been synthesized for Br 2 adsorption comparison. All of these four MOFs exhibited reversible uptake of Br 2 vapor judging by the unchanged PXRD patterns . Among four MOFs, Br 2 -loaded TCuI showed the most uptake amount of Br 2 (15.7 wt%), providing the formula to be TCuI ·0.33Br 2 . The different uptake amount of Br 2 for TCuX (X = CN, Cl, Br, I) should be mainly ascribed to the intermolecular interaction between CuX and Br 2 .
研究领域:
无机化学
·
材料化学
·
配位化学
·
多孔材料
·
气体吸附
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2016
·
IF 3.014
Huali Hao,Shulong Ye,Kaiping Yu,Peng Chen,Ruinan Gu,Peng Yu
The influence of alloying elements on the sintering behaviors of Cu is investigated by using Cu green samples doped with 0.5 wt% of Cr, Ti, Al, Mo, Nb and W. The sintering of Cu is greatly promoted by adding Cr, Ti and Al, but impeded by adding Mo, Nb and W. Among all alloying elements, Cr shows the most significant promoting effect, with the relative density of the Cu-0.5 wt% Cr sample being increased to 95% after sintering, about 5% higher than the pure Cu sample. Both the thermodynamic analysis and microstructure observation of the sintered samples suggest that the sintering enhancement can be attributed to the reduction of oxide layer on the Cu powder. The sintering-promoting elements are more affinitive to oxygen. Therefore, they are more likely to react with the oxide layer on the powder surface and facilitate the sintering.
研究领域:
材料科学
·
冶金学
·
粉末冶金
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Wenjie Shu,Yuxia Tang,Bingwen Su,Aijun Hong,Lin Lin,Xiaohui Zhou,Zhibo Yan,Jun-Ming Liu
Recently, the p-type semiconductor AgSbTe2 has received a great deal of attention due to its promising thermoelectric performance in intermediate temperatures (300–700 K). However, its performance is limited by the suboptimal carrier concentration and the presence of Ag2Te impurities. Herein, we synthesized AgSb1–xCuxTe2 (x = 0, 0.02, 0.04, and 0.06) and investigated the effect of Cu doping on the thermoelectric properties of AgSbTe2. Our results indicate that Cu doping suppresses the Ag2Te impurities, raises the carrier concentration, and results in an improved power factor (PF). The calculation reveals that Cu doping downshifts the Fermi energy level, reduces the energy band gap and the difference among several valence band maximums, and thereby explains the improvement of PF. In addition, Cu doping reduces the thermal conductivity, possibly attributed to the inhibition of Ag2Te impurities and the phonon softening of the AgSb1–xCuxTe2. Overall, Cu doping improves the ZT of AgSb1–xCuxTe2. Among all samples, AgSb0.96Cu0.04Te2 has a maximum ZT of ∼1.45 at 498 K and an average ZT of ∼1.11 from 298 to 573 K.
研究领域:
材料科学
·
热电学
·
半导体物理
·
能量转换
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
M.Z. Chu,C. Zhang,X.H. Liang,C.H. Hu,G.T. Ma,R.Y. Fang,Chengying Tang
The Au-Cu nanoalloys (NPs) were produced by NaBH 4 co-reduction from the mixture precursor solution of component Au and Cu, under the protection of sodium citrate stabilizer . The Au-Cu NPs encapsulated in SiO 2 , Au 5 Cu 5 @SiO 2 NPs, were then synthesized by the Stöber method based on the obtained Au-Cu NPs. The microstructure and particle sizes were characterized by TEM observation. The phase transition temperature of Au-Cu@SiO 2 was determined by DSC measurement. The surface tension, surface segregation and surface energy of Au-Cu NPs as a function of particle size and temperature were calculated by the theoretical model based on the thermodynamic properties of pure component of Au and Cu NPs, respectively. The thermodynamic parameters of Au-Cu system at various nanoscales were optimized on the basis of experimental and theoretical results in this work and previous results in literature. Based on the obtained the thermodynamic data set, the nano phase diagrams of the Au-Cu system at nanoscale were calculated, and the thermodynamic properties of Au-Cu nanometer system were obtained. The results show that the calculated results agree well with experimental work.
研究领域:
纳米材料
·
热力学
·
合金物理
·
相变
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2016
·Vol. 45
·期 12
·6095-6101
·
IF 1.491
Wang Yan,Han Jing,Ma Limin,Zuo Yong,Guo Fu
The composite approach, by incorporating small amounts of reinforcement particles in the solder matrix, has proven to be one of the effective ways to improve the reliability of solder joints. The effects of Cu addition on electromigration were investigated in this study by incorporating 2% volume fraction Cu particles into Sn-3.5Ag eutectic solder paste by the in situ process. The one-dimensional solder joints, designed to prevent the current crowding effect, were stressed under a constant current density of 10 4 A/cm 2 at room temperature, and the temperature of the sample could reach 105 ± 5°C due to the Joule heating effect. Doping 2 vol.% Cu was found to retard the electromigration phenomenon effectively. After electric current stressing for 528 h, the growth rate of an interfacial intermetallic compound (IMC) layer at the anode decreased 73% in contrast to that of Sn-3.5Ag solder joints, and the IMC layer at the cathode was almost unchanged. The polarization effect of Cu reinforced composite solder joints was also apparently mitigated. In addition, the surface damage of the composite solder joints was relieved by incorporating 2 vol.% Cu particles. Compared to Sn-3.5Ag solder joints, which had protruded Cu 6 Sn 5 and wrinkles of Sn-solder matrix on the surface, the solder joints with Cu addition had a more even surface.
研究领域:
材料科学
·
电子封装
·
可靠性工程
✓ 已验证
DOI
高影响因子
CRYSTENGCOMM
·
2019
·Vol. 22
·期 4
·678-685
·
IF 3.382
Xiao Shao,Tianyong Zhang,Bin Li,Yue Wu,Xiaoyuan Ma,Jingchao Wang,Shuang Jiang
Copper sulfide (Cu2−xS) is a kind of cation deficient transition metal sulfide, which has attracted great interest due to its unique properties that arise from degenerate vacancy-doping, particularly its tunable localized surface plasmon resonance (LSPR) properties. In this work, a range of vacancy-doped Cu2−xS nanocrystals (NCs) (Cu1.2S, Cu1.4S, Cu1.75S, and Cu1.94S NCs) with a size of around 10 nm was prepared with tunable LSPR through a hot injection method. The doping level was manipulated effectively by varying the injection volume of sulfur powder–oleic acid (S–OA) to finely tune the LSPR wavelength. Cu2−xS NCs with four different doping levels were investigated as photocatalysts for degradation of dyes. The Cu1.94S NCs with the highest LSPR energy exhibited the best photocatalytic activity due to the highest free carrier density, presumably influenced by Cu vacancies and the volume of the S–OA solution. Theoretical calculations of the free carrier density of Cu2−xS NCs are consistent with the order of the photocatalytic activity. The results demonstrate that the correlation of the photocatalytic activity with the corresponding concentration of free holes and the LSPR wavelength is of interest, which will provide inspiration for the design of non-noble metal catalysts by regulating the free hole concentration in degenerate p-doped Cu2−xS caused by cation vacancies.
研究领域:
材料科学
·
纳米技术
·
化学
✓ 已验证
DOI
高影响因子
RUSSIAN JOURNAL OF GENERAL CHEMISTRY
·
2021
·Vol. 91
·期 4
·726-731
·
IF 0.868
Xu Y.,Hu Y.,Bao Q.,Zhang J.,Liu B.,Zhang Z.,Zhang Q.,Zhang H.
Copper phyllosilicate has been synthesized from a solution of sodium silicate and copper nitrate by co-precipitation under acidic conditions followed by reduction under H 2 flow for using it as the Cu/SiO 2 catalyst. The catalyst has been characterized by XRD, XPS, FTIR and Raman spectra, EDS, BET, and TEM. It is confirmed that only copper phyllosilicate and SiO 2 exist in the catalyst precursor, and there has been no CuO. Physical and chemical properties of Cu/SiO 2 catalyst have been evaluated. The Cu/SiO 2 catalyst has not only a large specific surface area and abundant mesopores but also the advantages of high dispersion of copper nanoparticles and the combination of Cu 0 and Cu + . The catalyst demonstrates high activity and selectivity in the reaction of 2-butanol dehydrogenation to methyl ethyl ketone.
研究领域:
催化化学
·
材料科学
·
物理化学
·
纳米材料
·
有机合成
✓ 已验证
DOI
高影响因子
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
·
2023
·Vol. 120
·期 13
·e2220792120
·
IF 11.1
Junwei Zhang,Xikun Zhang,Chiwei Xu,Yiwen Liu,Jiaxi Xu,Zhonghao Miao,Haoxiang Yu,Lei Yan,Liyuan Zhang,Jie Shu
Selenium sulfide (SeS2) features higher electronic conductivity than sulfur and higher theoretical capacity and lower cost than selenium, attracting considerable interest in energy storage field. Although nonaqueous Li/Na/K-SeS2 batteries are attractive for their high energy density, the notorious shuttle effect of polysulfides/polyselenides and the intrinsic limitations of organic electrolyte have hindered the deployment of this technology. To circumvent these issues, here we design an aqueous Cu-SeS2 battery by encapsulating SeS2 in a defect-enriched nitrogen-doped porous carbon monolith. Except the intrinsic synergistic effect between Se and S in SeS2, the porous structure of carbon matrix has sufficient internal voids to buffer the volume change of SeS2 and provides abundant pathways for both electrons and ions. In addition, the synergistic effect of nitrogen doping and topological defect not only enhances the chemical affinity between reactants and carbon matrix but also offers catalytic active sites for electrochemical reactions. Benefiting from these merits, the Cu-SeS2 battery delivers superior initial reversible capacity of 1,905.1 mAh g−1 at 0.2 A g−1 and outstanding long-span cycling performance over 1,000 cycles at 5 A g−1. This work applies variable valence charge carriers to aqueous metal–SeS2 batteries, providing valuable inspiration for the construction of metal–chalcogen batteries.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF LUMINESCENCE
·
2023
·
IF 3.6
Li Wang,Fumin Lu,Xiaoman Li,Fangfang Hu,Hai Guo,Rongfei Wei
Luminescence glass is an inspiring scintillating material because of the unique merits including simple preparation process, mass production and low-cost. However, it is still a daunting challenge to explore the scintillating glass which can be applied in practical life. Herein, a novel Cu + doped borate glass scintillator was successfully fabricated under air atmosphere by introducing proper Si 3 N 4 in melting process. The resultant glass exhibits broadband luminescence under ultraviolet (UV) light or X-ray excitation. Through the low temperature thermal treatment, both luminescence induced by UV and X-ray can be significantly enhanced. The quantum efficiency reaches as high as 74.2%. And the sample endows superior thermal stability with the emission intensity at 573 K still maintaining 62.5% of that at 303 K. The X-ray excited luminescence is 37.8% of that of the commercial Bi 4 Ge 3 O 12 (BGO) crystal. Furthermore, the damaged sample even stimulated by high-energy X-ray can be restored to original level completely after heat treatment again. Besides, the sample presents outstanding optical thermometric performance based on the fluorescence decay lifetime. These findings confirm that the as-prepared Cu + doped borate glass is a promising candidate applied in the areas of scintillator and temperature sensor .
✓ 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）