17493-86-6Relevant articles and documents
Hierarchical Copper with Inherent Hydrophobicity Mitigates Electrode Flooding for High-Rate CO2 Electroreduction to Multicarbon Products
Niu, Zhuang-Zhuang,Gao, Fei-Yue,Zhang, Xiao-Long,Yang, Peng-Peng,Liu, Ren,Chi, Li-Ping,Wu, Zhi-Zheng,Qin, Shuai,Yu, Xingxing,Gao, Min-Rui
, p. 8011 - 8021 (2021/05/29)
Copper is currently the material with the most promise as catalyst to drive carbon dioxide (CO2) electroreduction to produce value-added multicarbon (C2+) compounds. However, a copper catalyst on a carbon-based gas diffusion layer electrode often has poor stability - especially when performing at high current densities - owing to electrolyte flooding caused by the hydrophobicity decrease of the gas diffusion layer during operation. Here, we report a bioinspired copper catalyst on a gas diffusion layer that mimics the unique hierarchical structuring of Setaria's hydrophobic leaves. This hierarchical copper structure endows the CO2 reduction electrode with sufficient hydrophobicity to build a robust gas-liquid-solid triple-phase boundary, which can not only trap more CO2 close to the active copper surface but also effectively resist electrolyte flooding even under high-rate operation. We consequently achieved a high C2+ production rate of 255 ± 5.7 mA cm-2 with a 64 ± 1.4% faradaic efficiency, as well as outstanding operational stability at 300 mA cm-2 over 45 h in a flow reactor, largely outperforming its wettable copper counterparts.
Synthesis of an Ag@AgCl catalyst with amorphous copper as the support and its catalytic performance in the reduction of 4-nitrophenol
Bao, Lei,Dong, Hanfeng,Fu, Xucheng,Gan, Wei,Hao, Hequn,Liu, Luying,Qin, Chenchen,Wang, Yujuan,Zhang, Jian
, p. 551 - 557 (2020/07/24)
The support used in a composite catalyst has an important influence on the catalytic performance of the catalyst. Amorphous metals have good electron-transfer properties and the presence of defect structures on the surface will introduce additional active sites and should be excellent catalyst supports. In this study, an Ag@AgCl composite catalyst with amorphous Cu (a-Cu) as the support is prepared by a two-step precipitation method at room temperature and a light irradiation reduction method. Compared to the Ag@AgCl and a-Cu, the catalytic rate of the Ag@AgCl/a-Cu composite catalytic rate was 2.04 times and 6.69 times faster during the reduction of 4-NP in NaBH4 aqueous solution. The high-performance catalytic efficiency and reusability of Ag@AgCl/a-Cu may be attributed to the synergistic effect between Ag@AgC and amorphous metal elements. This work may provide an effective reference for the synthesis of high activity catalysts using amorphous metals as supports.
Theoretical and Experimental Evaluation of the Reduction Potential of Straight-Chain Alcohols for the Designed Synthesis of Bimetallic Nanostructures
Ishijima, Masanao,Matsumoto, Takatoshi,Cuya Huaman, Jhon L.,Shinoda, Kozo,Uchikoshi, Masahito,Matsuo, Kohei,Suzuki, Kazumasa,Miyamura, Hiroshi,Balachandran, Jeyadevan
, p. 9432 - 9441 (2021/05/06)
Recently, the development of bimetallic nanoparticles with functional properties has been attempted extensively but with limited control over their morphological and structural properties. The reason was the inability to control the kinetics of the reduction reaction in most liquid-phase syntheses. However, the alcohol reduction technique has demonstrated the possibility of controlling the reduction reaction and facilitating the incorporation of other phenomena such as diffusion, etching, and galvanic replacement during nanostructure synthesis. In this study, the reduction potential of straight-chain alcohols has been investigated using molecular orbital calculations and experimentally verified by reducing transition metals. The alcohols with a longer chain exhibited higher reduction potential, and 1-octanol was found to be the strongest among alcohols considered. Furthermore, the experimental evaluation carried out via the synthesis of metallic Cu, Ni, and Co particles was consistent with the theoretical predictions. The reaction mechanism of metallic particle formation was also studied in detail in the Ni-1-octanol system, and the metal ions were confirmed to be reduced via the formation of nickel alkoxide. The results of this investigation were successfully implemented to synthesize Cu-Ni bimetallic nanostructures (core-shell, wire, and tube) via the incorporation of diffusion and etching besides the reduction reaction. These results suggest that the designed synthesis of a wide range of bimetallic nanostructures with more refined control has become possible.
Synthesis, Structure, DFT, and Biological Activity of Metal Complexes of Norfloxacin and Metformin Mixed Ligand
Abbass, L. M.,El-Shwiniy, W. H.,El-Telbany, M.,Sadeek, S. A.,Zordok, W. A.
, p. 1774 - 1782 (2021/11/01)
Abstract: A new series of mixed ligand metal complexes has been synthesized by the reaction of Co(II), Ni(II), Cu(II), Zr(IV), Pd(II), and Cd(II) with norfloxacin (NOR) and metformin hydrochloride (MF) in 1 : 1 : 1 molar ratio. The complexes have been characterized by FT-IR, UV-Vis, and 1H NMR spectra, TG/DTG and elemental analysis, molar conductance, and magnetic susceptibility data. According to FT-IR, NOR chelates with metal ions as a bidentate ligand via one oxygen of the carboxylate group and pyridone oxygen, and MF chelates with metal ions via two imine groups. Complexes have been identified as electrolytes. Electronic and magnetic data have indicated the octahedral structure for all complexes except square planar Pd(II) complex. Antibacterial and antifungal activities of the compounds have been tested against several species, and have indicated higher inhibition against micro-organisms for the metal complexes than the mixed ligands.
A Low-Temperature Molecular Precursor Approach to Copper-Based Nano-Sized Digenite Mineral for Efficient Electrocatalytic Oxygen Evolution Reaction
Chakraborty, Biswarup,Kalra, Shweta,Beltrán-Suito, Rodrigo,Das, Chittaranjan,Hellmann, Tim,Menezes, Prashanth W.,Driess, Matthias
, p. 852 - 859 (2020/02/28)
In the urge of designing noble metal-free and sustainable electrocatalysts for oxygen evolution reaction (OER), herein, a mineral Digenite Cu9S5 has been prepared from a molecular copper(I) precursor, [{(PyHS)2CuI(PyHS)}2](OTf)2 (1), and utilized as an anode material in electrocatalytic OER for the first time. A hot injection of 1 yielded a pure phase and highly crystalline Cu9S5, which was then electrophoretically deposited (EPD) on a highly conducting nickel foam (NF) substrate. When assessed as an electrode for OER, the Cu9S5/NF displayed an overpotential of merely 298±3 mV at a current density of 10 mA cm?2 in alkaline media. The overpotential recorded here supersedes the value obtained for the best reported Cu-based as well as the benchmark precious-metal-based RuO2 and IrO2 electrocatalysts. In addition, the choronoamperometric OER indicated the superior stability of Cu9S5/NF, rendering its suitability as the sustainable anode material for practical feasibility. The excellent catalytic activity of Cu9S5 can be attributed to the formation of a crystalline CuO overlayer on the conductive Cu9S5 that behaves as active species to facilitate OER. This study delivers a distinct molecular precursor approach to produce highly active copper-based catalysts that could be used as an efficient and durable OER electro(pre)catalysts relying on non-precious metals.
The composition dependent structure and catalytic activity of nanostructured Cu-Ni bimetallic oxides
Preethi, S.,Sundramoorthy, Ashok K.,Suresh Babu, K.,Vivek, S.
, p. 9691 - 9698 (2020/07/03)
Nanostructured bimetallic oxides have received a great amount of attention in the field of catalysis. Here, the influence of composition on the structure and catalytic activity of CuO/NiO bimetal oxides is reported. Oxides with different ratios of Cu : Ni (0 : 100, 25 : 75, 50 : 50, 75 : 25 and 100 : 0) were prepared via a hydrothermal process and subsequently heat-treated at 600 °C for 4 h. XRD and Raman spectroscopic analysis clearly indicated the co-existence of NiO and CuO phases in the bimetallic oxides. Electron microscopy studies revealed a reduction in particle size for the bimetallic oxide compared to the monometallic oxide. The highest catalytic activity with good recyclability for the reduction of 4-nitrophenol was observed with Cu50Ni50-600, having a rate constant of 5.08 × 10-3 s-1. Cyclic voltammetry investigations confirmed the high reactivity of Cu50Ni50-600 for 4-nitrophenol, showing a high oxidation current peak compared to that of other samples. The results show that the presence of CuO and NiO enhances the catalytic activity by their synergetic effect, unlike the monometal oxides. This journal is
Synthesis, Crystal Structures, and Thermolysis Studies of Heteronuclear Transition Metal Aluminum Alcoholates
Küsel, Sebastian,Krautscheid, Harald
, (2020/08/21)
Heteronuclear alcoholate complexes [M{Al(OiPr)4}2(bipy)] (2-M, M = Fe, Co, Ni, Cu, Zn) and [M{Al(OcHex)4}2(bipy)] (3-M, M = Fe, Co, Ni, Zn) are formed by adduct formation of [M{Al(OiPr)4}2] (1-M, M = Fe, Co, Ni, Cu, Zn) with 2,2'-bipyridine and transesterification reaction with cHexOAc. According to crystal structure analyses, in 2-M and 3-M the central transition metal ion M2+ is coordinated by two chelating Al(OR)4– moieties and one bipyridine ligand in an octahedral arrangement. Treating 1-Cu with 2,2'-bipyridine leads to a reduction process, whereat the intermediate [Cu{Al(OiPr)4}(bipy)2][Al(OiPr)4] (4) could be structurally characterized. During conversion of the iso-propanolate ligands in 1-Cu to cyclohexanolate ligands, Cu2+ is reduced to Cu+ forming [Cu{Al(OcHex)4}(py)2] (5). UV/Vis-spectra and results of thermolysis studies by TG/DTA-MS are reported.
Cylindrical shaped ZnO combined Cu catalysts for the hydrogenation of CO2 to methanol
Lei, Hong,Zheng, Ruheng,Liu, Yeping,Gao, Jiacheng,Chen, Xiang,Feng, Xiaoliang
, p. 13696 - 13704 (2019/05/17)
Hydrogenation of CO2 to chemicals is of great importance in the reduction of greenhouse gas emission. And the interaction and/or the boundary between Cu and ZnO played a crucial role in the performance of the Cu-ZnO catalyst for CO2 hydrogenation to methanol. In this work, cylindrical shaped ZnO was first synthesized via controlled hydrothermal precipitation of Zn(CO2CH3)2·2H2O, and Cu was further deposited on ZnO via in situ reduction in aqueous solution. Characterizations indicated that the crystallization degree of ZnO decreased with the increasing content of Cu, while the exposed surface area of Cu exhibited a volcano shaped curve. It was found that the cylindrical shaped ZnO combined Cu catalysts were active for the hydrogenation of CO2, and the space time yield of methanol reached 0.50 g-MeOH (g-cat h)-1 at H2/CO2 = 3, 240 °C, 3.0 MPa, and 0.54 mol (g-cat h)-1, but the methanol selectivity decreases with the reduction of the (002) polar plane of ZnO. The conversion of CO2 and methanol selectivity were discussed with the detected exposed Cu surface area and the number of oxygen vacancies.
Selective hydrogenation of quinolines over a CoCu bimetallic catalyst at low temperature
He, Zhen-Hong,Li, Na,Wang, Kuan,Wang, Wei-Tao,Liu, Zhao-Tie
, p. 120 - 126 (2019/04/10)
Quinoline derivatives are widely exist in the environment, and mainly separated from the coal tar pitch fraction. Hydrogenation of these compounds to 1,2,3,4-tetrahydroquinolines, an important class of natural products and medicinal agents, is a significant transformation of waste to valuable chemicals. In the present work, we developed a cheap and highly efficient Co3Cu1Ox bimetallic catalyst and used it for the hydrogenation of quinolines at a temperature down to 60 °C. The introduction of Cu into Co catalyst changed the physical and chemical features of Co catalyst, which was characterized by Raman spectra, N2-adsorption/desorption isotherms, H2-TPR and H2-TPD tests. The recycling experiments indicated the catalyst was stable and possessed good reusability. Importantly, the gram-scale experiment provided a high yield (92%) to the target product, demonstrating that the catalytic system has a potential practical application.
Pharmacological properties of dicyanidoaurate(I)-based complexes: characterization and single crystal X-ray analysis
Karada?, Ahmet,Aydin, Ali,Tekin, ?aban,Akba?, Hüseyin,Dede, Süreyya
, p. 860 - 878 (2019/03/11)
Absract: The synthesis of three bimetallic cyanido complexes with edbea [2,2′-(ethylenedioxy)bis(ethylamine)] ligand is reported. [NiII(μ-edbea)2{Au(μ-CN)2}2]n (1), [{CuII(edbea)}2{Au(μ-CN)2}4]n (2) and [CdII(edbea)2][Au(CN)2]2·H2O (3) were fully characterized by elemental, infrared, XRD (3), ESI-MS and thermal analysis. The DNA/BSA binding properties of these complexes were evaluated by spectrophotometric titration, fluorometric ethidium bromide kinetics, and DNA electrophoresis studies and their partially minor groove binding mode between the base pairs of DNA and electrostatic interaction between the amino acid residues of BSA were explained. The complexes were tested for their pharmacological properties. These molecules had excellent in vitro antiproliferative activity and also exhibited a strong tumor inhibiting effect against HT29, HeLa, C6 and Vero cell lines. These complexes had metastatic features as they are able to reduce cell migration activity and suppress tumor growth in vitro. Analysis of the DNA topoisomerase I relaxing activity indicates that the complexes do not inhibit topoisomerase I which regulates the topological states of the DNA double helix during DNA processing reactions. The TUNEL and DNA laddering assay results indicated that these compounds may destroy cell maintenance by triggering apoptosis. Immunohistochemistry staining analysis demonstrated that these complexes significantly decreased the expression of Bcl-2 in HeLa and HT29 cells while increasing the expression of P53 levels. Overall, the potent antiproliferative activity, low cytotoxic effect, good solubility, and micro molar range dosage observed for these complexes emphasizes their potential as anticancer drug candidates.
