Reaction Kinetics Mechanisms and Catalysis
·
2014
·Vol. 111
·期 2
·633-645
·
IF 0.983
Yue Chuan-Jun,Gu Li-Ping,Su Yang,Zhu Shao-Ping
Cu/MgO and MgO nested on the surface of Raney Cu were prepared by a wet-mixing method and used as catalyst for glycerol hydrogenolysis. The texture of Raney Cu/MgO was characterized by X-ray diffraction and transmission electron microscopy, Brunauer–Emmett–Teller, and CO 2 -temperature-programmed desorption techniques. Results indicated that MgO was well dispersed in the pores of Raney Cu. Moreover, Raney Cu with large specific surface area had a larger contact surface for MgO, and a new phase of Cu–MgO was produced. Glycerol hydrogenolysis was selectively catalyzed under the synergistic effect of Cu and MgO in Cu/MgO catalyst. Under the moderate conditions of 180 °C and 1 MPa H 2 , the conversion of glycerol was 36.2 wt% and the selectivity for 1,2-propanediol was ~85 wt% when chemical equilibrium.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2016
·
IF 3.698
Ying Han,Zhong-lin Chen,Ji-min Shen,Ji-he Wang,Wei-wei Li,Jun Li,Bin-yuan Wang,Li-na Tong
The role of Cu(II) in the reduction of N -nitrosodimethylamine (NDMA) with zero-valent metals was investigated by determining the effects of Cu(II) on the removal, kinetics, products, and mechanism. NDMA removal was enhanced, and all reactions followed a pseudo-first-order kinetic model except for the Fe and Fe/0.1 mM Cu(II) systems. The iron mass-normalized pseudo-first-order rate constants ( k MFe ) increased with the Cu(II) concentration. The zinc mass-normalized pseudo-first-order rate constants ( k MZn ) were identical to those with the Cu(II) concentrations from 0.1 mM to 1.0 mM and were higher with 2.0 mM Cu(II). The types of products detected were unchanged. Some unknown products were also found. NDMA was reduced to 1,1-dimethylhydrazine (unsymmetrical dimethylhydrazine , UDMH). Then, UDMH was reduced into dimethylamine (DMA) by the Fe/Cu(II) and Zn/Cu(II) systems. Catalytic hydrogenation was proposed as the reduction mechanism. Several copper species, such as Cu(OH) 2 in the Fe/Cu(II) system and Cu 2 O and Cu(OH) 2 in the Zn/Cu(II) system enhanced NDMA reduction. Differences between the Fe/Cu(II) and Zn/Cu(II) systems were caused by the reduction potentials and surface conditions of the different metals and the copper species in the various systems.
研究领域:
环境化学
·
水处理
·
催化
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2017
·
IF 3.615
Yong Zhang,Huiping Zhang,Ying Yan
A heterogeneous catalyst (Cu/ZSM-5) was prepared by a metal-organic chemical vapor deposition (MOCVD) method under nitrogen atmosphere using Cu(acac) 2 as the copper precursor, and further characterized by XRD , AAS , SEM, BET, H 2 -TPR and XPS as well as catalytic activity performance for the oxidation of toluene. N 2 adsorption data revealed that the samples (CVD-4) prepared by MOCVD with calcination at 500 °C for 4 h possessed higher surface areas than that (CVD-BC) not calcined. The results of XPS demonstrated that CVD-4 exhibited higher redox property and more surface oxygen species compared with CVD-BC and IM (Cu/ZSM-5 catalyst prepared by impregnation). In particular, the CVD-4 catalysts prepared by MOCVD with calcinations showed the highest catalytic activity for toluene oxidation with 90% conversion of toluene at 293 °C with the feed concentration of 1000 ppm and GHSV of 15,000 h −1 , which was lower than IM (310 °C). The results of a reaction durability test revealed that the Cu/ZSM-5 catalysts prepared by MOCVD possessed excellent durability for toluene oxidation for 63 h, while the conversion of toluene fell down from 90% to 60% after 48 h over IM catalyst.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2015
·Vol. 44
·期 35
·15645-15652
·
IF 4.197
Hanxing Chen,Teng Tu,Ming Wen,Qingsheng Wu
New Cu2O-on-Cu nanowires (NWs) are constructed to develop the visible-light-driven activity of photocatalysts via the facile self-assembly of Cu2O nanoparticles (NPs) on a Cu NW surface assisted by a structure director, followed in situ reduction. In the resultant Cu2O-on-Cu NWs, the Cu2O NPs, with a diameter of 10 nm, show good distribution on the 50 nm-sized Cu single-crystal NWs. Owing to the band-gap adjusting effect and high electron transportation, the coupling of narrow-band-gap semiconductor Cu2O and excellent conductor Cu can lead to the markedly enhanced high visible light photocatalytic activity of Cu2O-on-Cu NWs toward the degradation of dye pollutants including Rhodamine B (RhB), methyl orange (MO) and methyl blue (MB). The as-designed Cu2O-on-Cu heterostructured NWs exhibit higher performance for the catalytic degradation of dye compounds than pure Cu2O. Nearly 60%, 100%, and 85% conversion with reaction rate constants (k) of 0.0137, 0.0746 and 0.0599 min−1 can be achieved for the degradation of RhB, MO and MB, respectively. Besides the highly efficient transportation of electrons, Cu NWs have a strong capacity for oxygen activation, which results in the gathering of negative charges and rich chemisorbed oxygen onto the surface. This may be responsible for the high catalytic efficiency of the Cu2O-on-Cu NWs toward the degradation of organic pollutants.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2019
·
IF 3.973
Lingyan Yang,Liliang Chen,Yi-Chun Chen,Lei Kang,Jiantao Yu,Yuhang Wang,Chengjia Lu,Tsutomu Mashimo,Akira Yoshiasa,Chia-Hua Lin
Immiscible bimetallic Ag–Cu system has been synthesized by the pulsed plasma in liquid method with a graph of one pulse duration. Herein, by combining X-ray power diffraction, K-edge X-ray absorption near edge structure and high-resolution transmission electron microscopy, our results indicate that homogeneously alloyed Ag–Cu nanoparticles (Ag–Cu NAs) have the average diameter about 2.1 nm, composed by 48.5 at% Ag and 51.5 at% Cu with chemical analysis and the estimated lattice parameter was 3.873 Å. The antibacterial property of Ag–Cu NAs was detected against E. coli and S. aureus strains according to the colony formed abilities of bacteria on agar plates covered with the nanoparticles. With very short incubation period, Ag–Cu NAs completely inhibited the E. coli and S. aureus growth at an ultralow concentration. The mechanism of antibacterial property of Ag–Cu NAs was performed by the inductively coupled plasma-atomic emission spectrometry and the plane wave pseudopotential method implemented in the CASTEP package based on the density functional theory. The Ag + dissolution is correlated with antibacterial activity for Ag–Cu NAs-assisted antibacterial treatment. These findings obtained revealed that our Ag–Cu NAs could be served as a containing material of numerous bacteria-free products in order to avoid their bacterial contamination.
研究领域:
材料科学
·
微生物学
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产品关联
DOI
PubMed
高影响因子
Nano Research
·
2019
·Vol. 12
·期 5
·1187-1192
·
IF 8.515
Zhu Xiyue,Rong Hongpan,Zhang Xiaobin,Di Qiumei,Shang Huishan,Bai Bing,Liu Jiajia,Liu Jia,Xu Meng,Chen Wenxing,Zhang Jiatao
Control of surface structure at the atomic level can effectively tune catalytic properties of nanomaterials. Tuning surface strain is an effective strategy for enhancing catalytic activity; however, the correlation studies between the surface strain with catalytic performance are scant because such mechanistic studies require the precise control of surface strain on catalysts. In this work, a simple strategy of precisely tuning compressive surface strain of atomic-layer Cu 2 O on Cu@Ag (AL-Cu 2 O/Cu@Ag) nanoparticles (NPs) is demonstrated. The AL-Cu2O is synthesized by structure evolution of Cu@Ag core-shell nanoparticles, and the precise thickness-control of AL-Cu 2 O is achieved by tuning the molar ratio of Cu/Ag of the starting material. Aberration-corrected high-resolution transmission electron microscopy (AC-HRTEM) and EELS elemental mapping characterization showed that the compressive surface strain of AL-Cu 2 O along the [111] and [200] directions can be precisely tuned from 6.5% to 1.6% and 6.6% to 4.7%, respectively, by changing the number of AL-Cu 2 O layer from 3 to 6. The as-prepared AL-Cu 2 O/Cu@Ag NPs exhibited excellent catalytic property in the synthesis of azobenzene from aniline, in which the strained 4-layers Cu 2 O (4.5% along the [111] direction, 6.1% along the [200] direction) exhibits the best catalytic performance. This work may be beneficial for the design and surface engineering of catalysts toward specific applications.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 11
·6605-6614
·
IF 3.108
Ce Gao,Qingda An,Zuoyi Xiao,Shangru Zhai
Nowadays, processing of ultra-low sulfur fuel oil has been a hot topic of research all over the world; hence, an efficient adsorption process to tackle this issue is eliciting increasing attention. However, the preparation of high-performance adsorbents is still a challenge. Herein, zirconium-substituted mesoporous SBA-15 with highly dispersed active Cu(I) species has been successfully synthesized by our group at 493 K via a mild vapor-reduction method. The as-prepared material was characterized by powder X-ray diffraction (XRD), nitrogen adsorption and desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-vis diffuse reflectance (DRUV) spectroscopy. All characterization methods demonstrated that the Cu(I) species were highly dispersed in an ordered mesoporous framework with short channels rather than piled on the surface. The as-prepared materials also exhibited an excellent adsorption capacity for thiophene (up to 29.86 mg g−1 at 323 K). Pseudo-second-order kinetics model and Freundlich isotherm can well describe the adsorption kinetics and isotherm data, respectively. More remarkably, an ultrasound-assisted treatment can be effectively employed to regenerate adsorbent, with only a slight reduction in the adsorption capacity after five cycles.
研究领域:
材料科学
·
能源化学
·
环境工程
✓ 已验证
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 28
·16984-16990
·
IF 3.108
Jian-Min Zhu,Tian Xia,Kang-Kang Yan,Wei-Jui Chang,Xue-Gang Chen,Ying Ye,Ping-Ping Zhang
LiFePO4 is an effective battery material which has gained global focus. In this study, we prepared a novel Cu+-doped Li[Fe0.9Cu0.1Li0.1]PO4/C cathode material via a carbothermal reduction method using glucose as carbon source. X-ray diffraction (XRD) patterns and Rietveld refinement on the samples are consistent with the orthorhombic phase and showed that the substituting Cu+ ions and excess Li+ ions occupy the Fe sites. The micro-morphology of the samples indicates that Cu+ doping can decrease the particle size and maintain the crystal structure of LiFePO4/C. XP spectra confirmed that the surface oxidation states of Fe and Cu are +2 and +1, respectively. The as-prepared Li[Fe0.9Cu0.1Li0.1]PO4/C composite exhibits enhanced initial discharge capacity (148.8 mA h g−1) compared to the un-doped LiFePO4/C. The discharge capacity remains at 149.8 mA h g−1 after 50 cycles at a rate of 0.2C, which displayed an excellent cycling stability. Furthermore, the cyclic voltammetry (CV) and electrochemical impedance spectra (EIS) results showed that the Cu+-doped LiFePO4/C composite exhibits a higher lithium-ion diffusion coefficient and lower charge transfer resistance than the undoped counterparts. This study presents a novel Cu+-doped LiFePO4/C cathode material with enhanced electrochemical properties, which could be potentially applied as a battery material.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2024
·
IF 1.5
Zhou Lu-Wei,Chen Kai-Wei,Dai Xiao-Jun,Qiao Tai-Fei,Liu Hong-Yu,Lu Ji-Gen,Wang Peng,Gong Chun-Hui,Deng Shao-Gang,Xia Ming,Ni Fei,Tang Guo-Min,Zhang Yong-Bing,Yang Yi
Cu/Cu 2 O-modified activated carbon composites (Cu/Cu 2 O@AC) were synthesized via an one-step solvothermal method. The characterization results indicated that copper was uniformly dispersed on the surface of AC as nano-sized Cu 0 and Cu(I), which allowed Cu/Cu 2 O to make full contact with I − . The high specific surface area of Cu/Cu 2 O@AC and the affinity of Cu + for I − led to the equilibrium adsorption capacity within forty minutes. Additionally, the removal of trace I − (300 μg L −1 ) at pH = 3 by Cu/Cu 2 O@AC reached 96.4%. This work provides a promising application for the inexpensive and efficient capture of trace iodine from medical wastewater. Graphical abstract We synthesized Cu/Cu 2 O@AC composites for adsorption of iodide ions in solution.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2025
·Vol. 49
·期 7
·2889-2897
·
IF 2.5
Yanan Zhu,Yongchang Yang,Shiqiang Li,Chang Zhu,Zegang Qiu,Qianqian Zhu
The development of efficient materials for adsorption desulfurization has attracted much attention for the safety of humans and the ecosystem. Metal–organic frameworks have shown promise in removing organic sulfur compounds in liquid fuels, while another star material – MXene has rarely been applied in this field. In this study, Ti3C2Tx MXene/Cu-MOF composites with different MXene contents (3.3%, 6.7%, and 13.3%) were synthesized via an in situ precipitation method. Characterization showed that the Cu-MOF was successfully coated on the surface of Ti3C2Tx MXene and partially embedded between the MXene nanosheets, restraining the agglomeration of both MXene and the Cu-MOF. The optimal composite-3.3%MXene/Cu-MOF presented the largest surface area of 166.6 m2 g−1. Compared to MXene and Cu-MOF, 3.3%MXene/Cu-MOF exhibited an enhanced adsorption performance for methyl phenyl sulfide in the model fuel with an equilibrium adsorption capacity of 87.4 mg g−1. Furthermore, the effects of adsorption parameters, adsorption kinetics, adsorption isotherms, and the adsorption mechanism, and regenerative performance of 3.3%MXene/Cu-MOF were comprehensively discussed. A pseudo-second order kinetic model and the Langmuir adsorption isotherm were found to better explicate the adsorption behavior on 3.3%MXene/Cu-MOF, which exhibited a theoretical maximum adsorption capacity of 183.9 mg g−1. This work hopes to shed light on the material design for adsorption desulfurization.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Ze Li,Wen-Jie Li,Jun Guo,Zi-Yuan Wang,Xing Yang,Yu-Ke Zhu,Tian-En Shi,Yi-Xin Zhang,Jing Feng,Zhen-Hua Ge
SnSe materials have attracted extensive attention in thermoelectrics due to their low thermal conductivity. Nevertheless, the thermoelectric properties of n-type polycrystalline SnSe are still low, and metallic Sn distributed in the SnSe1–x materials would affect the repeatability of thermoelectric performance. Herein, the thermoelectric properties of n-type polycrystalline SnSe0.95-based composites are highly enhanced by heterogeneous Cu doping. The carrier concentration of the SnSe0.95 material was optimized by SnCl2 doping. The strategy of heterogeneous Cu doping is employed in further improving the thermoelectric performance of the SnCl2-doped SnSe0.95 materials. In addition, partial Cu+ doping tunes the electron concentration to enhance the Seebeck coefficient. Moreover, metallic Sn distributed along the grain boundaries can be stabilized by forming Cu6Sn5 alloys, which improve the thermal stability of bulk composites. Excessive Cu particles and SnCl2 precipitates strengthen phonon scattering for lowering the lattice thermal conductivity. Ultimately, a peak ZT of 1.55 is yielded at 773 K in the SnSe0.95–1 wt % SnCl2–1 wt % Cu bulk composite, whose mechanical hardness is also increased. Hence, these results promote a feasible approach to simultaneously enhance the thermoelectric and mechanical properties of n-type SnSe-based composites, which might be worth exploring in other thermoelectric materials.
研究领域:
材料科学
·
热电学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2024
·
IF 15.7
Lulu Sun,Shiyang Liu,Taifeng Liu,Dongqiang Lei,Nengchao Luo,Feng Wang
ABSTRACT Photocatalytic decomposition of sugars is a promising way of providing H 2 , CO, and HCOOH as sustainable energy vectors. However, the production of C 1 chemicals requires the cleavage of robust C−C bonds in sugars with concurrent production of H 2 , which remains challenging. Here, the photocatalytic activity for glucose decomposition to HCOOH, CO (C 1 chemicals), and H 2 on Cu/TiO 2 was enhanced by nitrogen doping. Owing to nitrogen doping, atomically dispersed and stable Cu sites resistant to light irradiation are formed on Cu/TiO 2 . The electronic interaction between Cu and nitrogen ions originates valence band structure and defect levels composed of N 2 p orbit, distinct from undoped Cu/TiO 2 . Therefore, the lifetime of charge carriers is prolonged, resulting in the production of C 1 chemicals and H 2 with productivities 1.7 and 2.1 folds that of Cu/TiO 2 . This work provides a strategy to design coordinatively stable Cu ions for photocatalytic biomass conversion.
研究领域:
化学工程
·
材料科学
·
可再生能源
✓ 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）