Articoli di riviste: "2-Bimetallics"

1

Yang, Chunpeng, Byung Hee Ko, Sooyeon Hwang, Zhenyu Liu, Yonggang Yao, Wesley Luc, Mingjin Cui et al. "Overcoming immiscibility toward bimetallic catalyst library". Science Advances 6, n. 17 (aprile 2020): eaaz6844. http://dx.doi.org/10.1126/sciadv.aaz6844.

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Bimetallics are emerging as important materials that often exhibit distinct chemical properties from monometallics. However, there is limited access to homogeneously alloyed bimetallics because of the thermodynamic immiscibility of the constituent elements. Overcoming the inherent immiscibility in bimetallic systems would create a bimetallic library with unique properties. Here, we present a nonequilibrium synthesis strategy to address the immiscibility challenge in bimetallics. As a proof of concept, we synthesize a broad range of homogeneously alloyed Cu-based bimetallic nanoparticles regardless of the thermodynamic immiscibility. The nonequilibrated bimetallic nanoparticles are further investigated as electrocatalysts for carbon monoxide reduction at commercially relevant current densities (>100 mA cm−2), in which Cu0.9Ni0.1 shows the highest multicarbon product Faradaic efficiency of ~76% with a current density of ~93 mA cm−2. The ability to overcome thermodynamic immiscibility in multimetallic synthesis offers freedom to design and synthesize new functional nanomaterials with desired chemical compositions and catalytic properties.

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Smith, KA, GB Deacon, WR Jackson e JM Miller. "Preparation and Reactivity of Some Phenyl-bismuth(III) Quinolin-8-olate Derivatives". Australian Journal of Chemistry 49, n. 2 (1996): 231. http://dx.doi.org/10.1071/ch9960231.

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The bimetallics [ PhBi (Ox)2( NaX )n] (Ox- = quinolin-8-olate: X = Cl , Br or I), containing variable amounts of sodium halides, have been prepared by reaction of PhBiX2 with Na(Ox) (mole ratio 1 : 2) or of Ph2BiX with Na(Ox) (mole ratio 1 : 1) in ethanol. A similar preparation has given [ PhBi ( MeOx )2( NaI )n] ( MeOx - = 2-methylquinolin-8-olate) . The bimetallics have been characterized by X-ray powder photography, f.a.b . mass spectrometry and 1H n.m.r. and electronic spectroscopy. Sodium halide-free PhBi (Ox)2 was obtained from the reaction of Ph2BiCl with Na(Ox) in the presence of 15-crown-5, or from treatment of PhBiI2 or Ph2BiI with NBu4(Ox). Reaction of equimolar amounts of PhBiI2 and Na(Ox) gives Bi(Ox)2I, which can also be obtained from BiI3 and Na(Ox) in a 1:1 or 1:2 stoichiometry. Treatment of PhBiI2 with M(0x) (M = Na or K) in a 1:3 mole ratio yields [ MPhBi (Ox)3] bimetallics, which appear to contain both chelating and unidentate Ox ligands from their electronic spectra.

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Verma, Alkadevi, Rajeev Kumar Gupta, Madhulata Shukla, Manisha Malviya e Indrajit Sinha. "Ag–Cu Bimetallic Nanoparticles as Efficient Oxygen Reduction Reaction Electrocatalysts in Alkaline Media". Journal of Nanoscience and Nanotechnology 20, n. 3 (1 marzo 2020): 1765–72. http://dx.doi.org/10.1166/jnn.2020.17154.

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The alkaline medium oxygen reduction reaction (ORR) activities of Ag–Cu bimetallic nanoparticles (BNPs), consisting of neighboring Ag and Cu domains, were studied and compared with those of pure Ag and Cu nanoparticles prepared by the same polyol route. Three variations of Ag–Cu BNPs viz. Ag–Cu (4:1), Ag–Cu (2:1), Ag–Cu (1:1) BNPs were considered. The electrocatalytic performances of these nanoparticles were investigated by using different techniques, such as cyclic voltammetry (CV) and linear sweep voltammograms (LSV). The Ag–Cu bimetallics demonstrated synergistic ORR electrocatalytic activity compared to pure Ag or Cu. Optimum values of these parameters were observed for Ag–Cu (4:1) BNPs. According to LSV, the reduction peak position is at lower applied potential and showed higher intensity for the Ag–Cu (4:1) as compared to Ag–Cu (2:1) and Ag–Cu (1:1) BNPs. Density Functional Theory (DFT) calculations show that charge transfer from Cu to Ag (in the bimetallic nanoparticles) results in their stronger oxygen interaction and water activation properties relative to that of pure Ag nanoparticles.

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Agrotis, Stefanos, Daren J. Caruana, Albertus Denny Handoko, Mustafa Emre Sener e Oliver S. J. Hagger. "Atmospheric Pressure Plasma Jet Synthesis and Characterization of Copper-Silver Bimetallic Materials as Electrocatalysts for CO₂ Reduction". ECS Meeting Abstracts MA2024-01, n. 24 (9 agosto 2024): 1403. http://dx.doi.org/10.1149/ma2024-01241403mtgabs.

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Copper-silver (Cu-Ag) bimetallics and alloys are attractive due to their enhanced performance compared to their parent metals in various fields including electronics, batteries, biomedicine, solar technology, energy storage, and catalysis.[1] Existing methods for synthesizing Cu-Ag bimetallics suffer from major drawbacks such as intense temperature and pressure conditions, pre and post-treatment processes, and multiple time-consuming steps.[2, 3] In this work, Cu-Ag bimetallic films were synthesized under various ratios for the first time using a newly developed Atmospheric Pressure Plasma Jet (APPJ) system. Synthesis was done in a single step, in under 15 minutes. The samples exhibited strong adhesion onto various substrates such as glass and glassy carbon. This direct-deposition technique requires low power input (<50 W) without the need for any pre- or post-treatment processes and with little to no waste. This contrasts with wet chemistry, where deposition normally takes 12-24 hours followed by thermal processes that produce several waste products.[4] Considering the high melting points (MP) of pure Cu and Ag (MP of Cu is ca. 1,085 °C and MP of Ag is ca. 962 °C), and the fact that they are immiscible, the formation of Cu-Ag alloys usually requires a high amount of energy under intense conditions.[5] These Cu-Ag films were characterized via cyclic voltammetry (CV), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). Here, we demonstrate that by only mixing low-concentration metal salt solutions and using a neutral gas (helium), we can readily synthesize metal alloys while controlling their thickness, shape, composition, and metal ratios. From an electrochemical point of view, APPJ drives the reduction of metal cations from the presence of free electrons. This suggests the presence of a medium that is considered either as an electrode, due to the presence of electrons, or as an electrolyte, due to their electrical conduction.[6] These plasma-synthesized materials were tested as electrocatalysts for reducing atmospheric carbon dioxide (CO2) under various potentials. The performance of these catalysts was assessed via electrochemical surface area (ECSA), electrochemical impedance spectroscopy (EIS), and pulse voltammetry techniques. Copper is the only heterogeneous catalyst that converts CO2 into valuable chemicals, such as hydrocarbons, aldehydes, and alcohols.[7] Interestingly, we illustrate that the addition of silver improves the catalytic activity of copper toward CO2 reduction under low potentials. This is a desirable property given the anticipated transition to green energy. References Tantawy, H.R., et al., Novel synthesis of bimetallic Ag-Cu nanocatalysts for rapid oxidative and reductive degradation of anionic and cationic dyes. Applied Surface Science Advances, 2021. 3: p. 100056. Zhang, X., et al., Microstructures and properties of 40Cu/Ag (Invar) composites fabricated by powder metallurgy and subsequent thermo-mechanical treatment. Metallurgical and Materials Transactions A, 2018. 49: p. 1869-1878. Rajashekhar, B., et al., Electro co-deposition of copper-silver nanocrystallite alloy cluster: A way for tunable SERS substrate development. Materials Letters: X, 2022. 15: p. 100157. Jie, S., et al., Preparation of copper–silver alloy with different morphologies by a electrodeposition method in 1-butyl-3-methylimidazolium chloride ionic liquid. Bulletin of Materials Science, 2019. 42: p. 1-4. Banhart, J., et al., Electronic properties of single-phased metastable Ag-Cu alloys. Physical Review B, 1992. 46(16): p. 9968. Rumbach, P., et al., The solvation of electrons by an atmospheric-pressure plasma. Nature communications, 2015. 6(1): p. 7248. Kuhl, K.P., et al., New insights into the electrochemical reduction of carbon dioxide on metallic copper surfaces. Energy & Environmental Science, 2012. 5(5): p. 7050-7059.

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Lee, Shung-Ik, John M. Vohs e Raymond J. Gorte. "A Study of SOFC Anodes Based on Cu-Ni and Cu-Co Bimetallics in CeO[sub 2]-YSZ". Journal of The Electrochemical Society 151, n. 9 (2004): A1319. http://dx.doi.org/10.1149/1.1774184.

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Deacon, GB, CM Forsyth, WC Patalinghug, AH White, A. Dietrich e H. Schumann. "Organolanthanoids. XVII. The Synthesis of Bis(diphenylphosphinocyclopentadienyl)ytterbium(II) and Derived Heterobimetallic Complexes [Yb(thf)n(C5H4PPh2)2Z] [Z=Ni(CO)2, Mo(CO)4 or PtMe2; n = 1 or 2; thf = Tetrahydrofuran]. The X-Ray Crystal-Structure of [Yb(thf)2(C5H4PPh2)2Ni(CO)2]". Australian Journal of Chemistry 45, n. 3 (1992): 567. http://dx.doi.org/10.1071/ch9920567.

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Reaction of diphenylphosphinocyclopentadiene with Yb (C6F5)2 or with ytterbium metal and Hg(C6F5)2 in tetrahydrofuran ( thf ) gives, after workup with toluene, the phosphinoytter-bocene , [Yb (C5H4PPh2)2( thf )]. Treatment with thf or with N,N,N′,N′- tetramethylethane-1,2-diamine ( tmen ) yields [ Yb (C5H4PPh2)2L2] (L = thf or L2 = tmen ). Redox trans- metallation between ytterbium metal and Tl (C5H4PPh2) in l,2-dimethoxyethane ( dme ) gives thallium metal and [ Yb (C5H4PPh2)2(dme )]. The ytterbium-transition metal hetero-bimetallics [ Yb ( thf ) (C2H4PPh2)2Z]. nPhMe [Z = Ni(CO)2, Mo(CO)4 or PtMe2, n = 2/3 or 1] have been prepared by reaction of [ Yb ( thf )(C5H4PPh2)2] with Ni(CO)2(PPh3)2, Mo(CO)4( nbd ) ( nbd = norbornadiene ) or PtMe2(cod) (cod = cycloocta-1,5-diene) in toluene. Treatment of the heterobimetallics with tetrahydrofuran [Z = PtMe2 or Mo(CO)4] or a preparation in thf /toluene [Z = Ni(CO)2] yields [ Yb ( thf )2(C5H4PPh2)2PtMe2]. thf, [ Yb ( thf )2(C2H4PPh2)2Mo(CO)4]. thf and [ Yb ( thf )2 (C5H4PPh2)2Ni(CO)2]. The X-ray crystal structure of the last compound (triclinic, space group Pi, a 14.514(5), b 13.565(1), c 10.866(5) 93.11(2), β 104.65(3), γ 97.25(2)�, U 2045 � 3 , Z 2, 5141 data refined to R 0.031) reveals eight-coordinate ytterbium with a pseudo-tetrahedral arrangement of two thf ligands and the cyclopentadienyl ring centroids of two ή5 -diphenylphosphinocyclopentadienide ligands . The latter are also bonded through phosphorus to the Ni(CO)2 group, resulting in tetrahedral stereochemistry for nickel. Infrared spectroscopy suggests the presence of ytterbium- isocarbonyl bonding in solid [ Yb ( thf )(C2H4PPh2)2Z] [Z = Ni(CO)2 or Mo(CO)4].

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7

Ding, Shengda, Pokhraj Ghosh, Marcetta Y. Darensbourg e Michael B. Hall. "Interplay of hemilability and redox activity in models of hydrogenase active sites". Proceedings of the National Academy of Sciences 114, n. 46 (30 ottobre 2017): E9775—E9782. http://dx.doi.org/10.1073/pnas.1710475114.

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The hydrogen evolution reaction, as catalyzed by two electrocatalysts [M(N2S2)·Fe(NO)2]+, [Fe-Fe]+ (M = Fe(NO)) and [Ni-Fe]+ (M = Ni) was investigated by computational chemistry. As nominal models of hydrogenase active sites, these bimetallics feature two kinds of actor ligands: Hemilabile, MN2S2 ligands and redox-active, nitrosyl ligands, whose interplay guides the H2 production mechanism. The requisite base and metal open site are masked in the resting state but revealed within the catalytic cycle by cleavage of the MS–Fe(NO)2 bond from the hemilabile metallodithiolate ligand. Introducing two electrons and two protons to [Ni-Fe]+ produces H2 from coupling a hydride temporarily stored on Fe(NO)2 (Lewis acid) and a proton accommodated on the exposed sulfur of the MN2S2 thiolate (Lewis base). This Lewis acid–base pair is initiated and preserved by disrupting the dative donation through protonation on the thiolate or reduction on the thiolate-bound metal. Either manipulation modulates the electron density of the pair to prevent it from reestablishing the dative bond. The electron-buffering nitrosyl’s role is subtler as a bifunctional electron reservoir. With more nitrosyls as in [Fe-Fe]+, accumulated electronic space in the nitrosyls’ π*-orbitals makes reductions easier, but redirects the protonation and reduction to sites that postpone the actuation of the hemilability. Additionally, two electrons donated from two nitrosyl-buffered irons, along with two external electrons, reduce two protons into two hydrides, from which reductive elimination generates H2.

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ADURIZ, H. R., P. BODNARIUK, B. COQ e F. FIGUERAS. "ChemInform Abstract: Alumina-Supported Bimetallics of Palladium Alloyed with Germanium, Tin, Lead, or Antimony from Organometallic Precursors. Part 2. Gas-Phase Hydrogenation of 2-Methyl-1-buten-3-yne (Valylene) and 2-Methyl-1,3- butadiene (Isoprene)." ChemInform 22, n. 27 (23 agosto 2010): no. http://dx.doi.org/10.1002/chin.199127096.

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ADURIZ, H. "Alumina-supported bimetallics of palladium alloyed with germanium, tin, lead, or antimony from organometallic precursors II. gas-phase hydrogenation of 2-methyl-1-buten-3-yne (valylene) and 2-methyl-1,3-butadiene (isoprene)". Journal of Catalysis 129, n. 1 (maggio 1991): 47–57. http://dx.doi.org/10.1016/0021-9517(91)90008-r.

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Cooke, Paul A., Caroline O'Dowd, Michael G. S. Londesborough, Josef Holub, Bohumil Štı́br, Mark Thornton-Pett, William Clegg, Simon J. Teat e John D. Kennedy. "B-frame supported bimetallics. ‘Composite cluster’ compounds and the structures of [2,7-(η5-C5Me5)2-nido-2,7,8,6-Ir2CSB6H8] and its 9-chloro derivative. Synchrotron and conventional X-ray studies". Journal of Organometallic Chemistry 614-615 (dicembre 2000): 57–60. http://dx.doi.org/10.1016/s0022-328x(00)00592-1.

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Soto, Joesene J., e Hector Abruna. "From Synthesis to Application: Ni₃ Fe N As Oxygen Reduction Electrocatalyst in Anion Exchange Membrane Fuel Cells". ECS Meeting Abstracts MA2023-02, n. 41 (22 dicembre 2023): 2039. http://dx.doi.org/10.1149/ma2023-02412039mtgabs.

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Catalysis has played a crucial role in advancing and commercializing energy conversion technologies. It is essential to identify abundant, active, and stable materials to enable the reliable and cost-efficient use of catalysts in renewable technologies such as fuel cells (FCs) and electrolyzers. Suitable candidates, like nonprecious metals, can be found in the transition metals' first row, where materials like bimetallics, metal oxides, and metal nitrides can be obtained. Recently, these materials have shown high activity toward the Oxygen Reduction Reaction (ORR) and the Oxygen Evolution Reaction (OER) in an alkaline medium, which can be related to good performance in FCs and electrolyzers. However, most of the studies do not go further than half-cell reactions. In this study, we explored the synthesis of a metal nitride, Ni3FeN, and its application as a cathode material in hydrogen fuel Anion Exchange Membrane Fuel Cells (AEMFC). A one-step ammonolysis synthesis was done to obtain Ni3FeN supported on carbon. Various metal loadings were synthesized with nanoparticles sizes of 7 ± 2 nm and 10 ± 4 nm for 40% and 60%, respectively, revealed with Transmission Electron Microscopy (TEM). High-resolution Scanning Transmission Electron Microscopy (STEM) images and Energy Dispersive X-ray (EDX) mapping analysis revealed a metal nitride core and a metal oxide shell of ca. 3 nm. The bulk electronic structure was further evaluated using X-ray Absorption Spectroscopy (XAS), where the EXAFS modeling suggests a bulk nitride electronic structure. Consequently, cyclic voltammetry (CV) was used to investigate the electrochemical properties and ORR performance of the Ni3FeN catalyst in 1 M KOH. The catalyst exhibited a stable electrochemical structure with a slight decrease in E1/2 of 10 mV (from 0.85 V to 0.84 V) during a 100 K ORR accelerated durability test (ADT). In addition, Levich and Rotating Ring Disk Electrode (RRDE) analyses showed that the number of electrons transferred during the ORR was consistent with a 4-electron pathway. Furthermore, the Ni3FeN catalyst was tested as the cathode in an AEMFC, obtaining a power density output of 400 mW/cm2, highlighting its potential for alkaline medium fuel cell applications.

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Zheng, B., L. Deloux, E. Skrzypczak-Jankun, B. V. Cheesman, S. Pereira, M. Srebnik e M. Sabat. "A novel class of organometallic complexes: 1,1-bimetallics of boron and zirconium". Journal of Molecular Structure: THEOCHEM 374, n. 1-3 (gennaio 1996): 291–97. http://dx.doi.org/10.1016/s0166-1280(96)80083-2.

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Katti, Kattesh V., e Ronald G. Cavell. "Application of phosphine and arsine-phosphoranimine backbones to the formation of early-late transition-metal bimetallics. Synthesis and characterization of new titanium-palladium frameworks: [cyclic]-(.eta.5-C5H5)Cl2TiN:PPh2(CH2)xEPh2PdCl2 (x = 1, E = P; x = 2, E = As)". Organometallics 10, n. 3 (27 marzo 1991): 539–41. http://dx.doi.org/10.1021/om00049a007.

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Pradhan, Alaka Nanda, Shivankan Mishra, Urminder Kaur, Bikram Keshari Rout, Jean-François Halet e Sundargopal Ghosh. "Bimetallic Perthiocarbonate Complexes of Cobalt: Synthesis, Structure and Bonding". Molecules 29, n. 11 (6 giugno 2024): 2688. http://dx.doi.org/10.3390/molecules29112688.

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The syntheses and structural elucidation of bimetallic thiolate complexes of early and late transition metals are described. Thermolysis of the bimetallic hydridoborate species [{Cp*CoPh}{µ-TePh}{µ-TeBH3-ĸ2Te,H}{Cp*Co}] (Cp* = ɳ5-C5Me5) (1) in the presence of CS2 afforded the bimetallic perthiocarbonate complex [(Cp*Co)2(μ-CS4-κ1S:κ2S′)(μ-S2-κ2S″:κ1S‴)] (2) and the dithiolene complex [(Cp*Co)(μ-C3S5-κ1S,S′] (3). Complex 2 contains a four-membered metallaheterocycle (Co2S2) comprising a perthiocarbonate [CS4]2− unit and a disulfide [S2]2− unit, attached opposite to each other. Complex 2 was characterized by employing different multinuclear NMR, infrared spectroscopy, mass spectrometry, and single-crystal X-ray diffraction studies. Preliminary studies show that [Cp*VCl2]3 (4) with an intermediate generated from CS2 and [LiBH4·THF] yielded thiolate species, albeit different from the cobalt system. Furthermore, a computational analysis was performed to provide insight into the bonding of this bimetallic perthiocarbonate complex.

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Chen, Lifang, Wei Liu, Haisong Feng, Yingyu Ren, Chunyuan Chen, Si Wang, Pan Yin, Yusen Yang, Xin Zhang e Min Wei. "Oxygen binding energy of doped metal: a shortcut to efficient Ni-based bimetallic catalysts for the hydrodeoxygenation reaction". Catalysis Science & Technology 11, n. 13 (2021): 4376–86. http://dx.doi.org/10.1039/d1cy00496d.

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OBE is a convenient and effective descriptor to search for Ni-based bimetallic catalysts. Ni–M (M = Fe, Co, Mo, Ru) bimetallic catalysts were identified as highly active samples for furfural (FAL) HDO to 2-methylfuran (2-MF).

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Matsinov, S. A., V. A. Kalinichenko e A. A. Andrushevich. "Prospects of coating application for improving surface properties of cast composite materials". Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY), n. 2 (11 giugno 2024): 63–71. http://dx.doi.org/10.21122/1683-6065-2024-2-63-71.

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Foundry production is a versatile industry that allows the production of products of almost any configuration and geometric dimensions. These products can be made from materials based on various metals and alloys, bimetallics, and composite materials. The obtained products can have uniform or gradient properties. However, to obtain a product with significantly different properties on the surface and in the volume from the casting, it is expedient to apply coatings with desired properties on the castings that complement the properties, allowing the improvement of coating performance. The paper focuses on the production of cast composite materials with improved surface properties. Various types of coatings based on high‑entropy alloys, cermets, polymers, carbon nanotubes, capable of enhancing the properties of cast composite materials, are considered. The classification and peculiarities of applying these coatings on the surface of composite materials are presented. The prospects of using these coatings to improve the properties of cast composite materials are shown.

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Zhang, Yunya, Weijian Diao, John R. Monnier e Christopher T. Williams. "Pd–Ag/SiO2 bimetallic catalysts prepared by galvanic displacement for selective hydrogenation of acetylene in excess ethylene". Catalysis Science & Technology 5, n. 8 (2015): 4123–32. http://dx.doi.org/10.1039/c5cy00353a.

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A series of bimetallic Pd–Ag/SiO₂ catalysts with Ag enriched on the surface were prepared by galvanic displacement. The bimetallic effect for these catalysts on acetylene hydrogenation was discussed.

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Hu, Quan Yuan, e Guochen Jia. "Synthesis and electrochemical properties of bimetallic η5-indenyl ruthenium complexes". Canadian Journal of Chemistry 87, n. 1 (1 gennaio 2009): 134–38. http://dx.doi.org/10.1139/v08-106.

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Treatment of RuCl(dppm)(η5-C9H7) with alkynes HC≡C(C6H4)nC≡CH (n = 1, 2) in the presence of TlPF6 and t-BuONa affords the bimetallic ruthenium acetylide complexes [(η5-C9H7)(dppm)Ru]2(µ-C≡C(C6H4)nC≡C). Reactions of the hydride complex RuH(dppm)(η5-C9H7) with HC≡C(C6H4)nC≡CH (n = 1, 2) in refluxing toluene give the bimetallic ruthenium alkenyl complexes [(η5-C9H7)(dppm)Ru]2(µ-CH=CH(C6H4)nCH=CH). The electrochemical properties of the new complexes have been investigated by cyclic voltammetry, which reveals that the organic spacer –CH=CHC6H4CH=CH– is more effective than –C≡CC6H4C≡C– in mediating electronic communication between the two ruthenium moieties.Key words: ruthenium, bimetallic, acetylide, insertion, electrochemistry.

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Coq, B., P. S. Kumbhar, C. Moreau, P. Moreau e M. G. Warawdekar. "Liquid phase hydrogenation of cinnamaldehyde over supported ruthenium catalysts: Influence of particle size, bimetallics and nature of support". Journal of Molecular Catalysis 85, n. 2 (novembre 1993): 215–28. http://dx.doi.org/10.1016/0304-5102(93)80103-2.

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Wu, Xiang-Wen, Shi Yin, Wan-Fu Wu e Jian-Ping Ma. "Synthesis and characterization of two novel bimetallic macrocyclic complexes generated from 1,2,4-triazole-containing semi-rigid ligands andM(NO3)2units (M= Ni and Zn)". Acta Crystallographica Section C Structural Chemistry 72, n. 4 (9 marzo 2016): 285–90. http://dx.doi.org/10.1107/s205322961600348x.

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Bimetallic macrocyclic complexes have attracted the attention of chemists and various organic ligands have been used as molecular building blocks, but supramolecular complexes based on semi-rigid organic ligands containing 1,2,4-triazole have remained rare until recently. It is easier to obtain novel topologies by making use of asymmetric semi-rigid ligands in the self-assembly process than by making use of rigid ligands. A new semi-rigid ligand, 3-[(pyridin-4-ylmethyl)sulfanyl]-5-(quinolin-2-yl)-4H-1,2,4-triazol-4-amine (L), has been synthesized and used to generate two novel bimetallic macrocycle complexes, namely bis{μ-3-[(pyridin-4-ylmethyl)sulfanyl]-5-(quinolin-2-yl)-4H-1,2,4-triazol-4-amine}bis[(methanol-κO)(nitrato-κ2O,O′)nickel(II)] dinitrate, [Ni2(NO3)2(C17H14N6S)2(CH3OH)2](NO3)2, (I), and bis{μ-3-[(pyridin-4-ylmethyl)sulfanyl]-5-(quinolin-2-yl)-4H-1,2,4-triazol-4-amine}bis[(methanol-κO)(nitrato-κ2O,O′)zinc(II)] dinitrate, [Zn2(NO3)2(C17H14N6S)2(CH3OH)2](NO3)2, (II), by solution reactions with the inorganic saltsM(NO3)2(M= Ni and Zn, respectively) in mixed solvents. In (I), two NiIIcations with the same coordination environment are linked byLligands through Ni—N bonds to form a bimetallic ring. Compound (I) is extended into a two-dimensional network in the crystallographicacplaneviaN—H...O, O—H...N and O—H...O hydrogen bonds, and neighbouring two-dimensional planes are parallel and form a three-dimensional structureviaπ–π stacking. Compound (II) contains two bimetallic rings with the same coordination environment of the ZnIIcations. The ZnIIcations are bridged byLligands through Zn—N bonds to form the bimetallic rings. One type of bimetallic ring constructs a one-dimensional nanotubeviaO—H...O and N—H...O hydrogen bonds along the crystallographicadirection, and the other constructs zero-dimensional molecular cagesviaO—H...O and N—H...O hydrogen bonds. They are interlinked into a two-dimensional network in theacplane through extensive N—H...O hydrogen bonds, and a three-dimensional supramolecular architecture is formedviaπ–π interactions between the centroids of the benzene rings of the quinoline ring systems.

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Wang, Xiang, Feng Li, Wenzhu Li, Wenbing Gao, Yu Tang e Rong Li. "Hollow bimetallic cobalt-based selenide polyhedrons derived from metal–organic framework: an efficient bifunctional electrocatalyst for overall water splitting". Journal of Materials Chemistry A 5, n. 34 (2017): 17982–89. http://dx.doi.org/10.1039/c7ta03167j.

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Hollow bimetallic cobalt-based selenide polyhedrons MxCo_1−xSe₂ were successfully synthesized by a simple solvothermal strategy using bimetallic MOFs as template. This catalyst exhibits excellent electrocatalytic performance for overall water splitting.

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Bustinza, Ainhoa, Marina Frías, Yuefeng Liu e Enrique García-Bordejé. "Mono- and bimetallic metal catalysts based on Ni and Ru supported on alumina-coated monoliths for CO2 methanation". Catalysis Science & Technology 10, n. 12 (2020): 4061–71. http://dx.doi.org/10.1039/d0cy00639d.

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A bimetallic catalyst consisting of Ni nanoparticles interspersed with atomic Ru on alumina coated monolith afforded higher activity than other mono and bimetallic catalysts in CO₂ methanation, providing low pressure drop at high space velocity.

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Zheng, Yingting, Xiqian Wang, Chao Liu, Baoqiu Yu, Wenliang Li, Hailong Wang, Tingting Sun e Jianzhuang Jiang. "Triptycene-supported bimetallic salen porous organic polymers for high efficiency CO2 fixation to cyclic carbonates". Inorganic Chemistry Frontiers 8, n. 11 (2021): 2880–88. http://dx.doi.org/10.1039/d1qi00163a.

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Abstract (sommario):

Triptycene units in bimetallic salen POPs are envisaged to support the alignment of bimetallic salen macrocycles in side walls of channels for exposing more metal active sites resulting in the high efficiency coupling reaction of epoxides with CO₂.

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Chen, Ri, Siqi Lv, Yunying Xu, Zicong Lin, Guoying Zhang, Jian Wang, Bocheng Wang, Wenxia Wang, Igor Zhitomirsky e Yong Yang. "Design and Fabrication of MoCuOx Bimetallic Oxide Electrodes for High-Performance Micro-Supercapacitor by Electro-Spark Machining". Micromachines 16, n. 1 (25 dicembre 2024): 7. https://doi.org/10.3390/mi16010007.

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Abstract (sommario):

Transition metal oxides, distinguished by their high theoretical specific capacitance values, inexpensive cost, and low toxicity, have been extensively utilized as electrode materials for high-performance supercapacitors. Nevertheless, their conductivity is generally insufficient to facilitate rapid electron transport at high rates. Therefore, research on bimetallic oxide electrode materials has become a hot spot, especially in the field of micro-supercapacitors (MSC). Hence, this study presents the preparation of bimetallic oxide electrode materials via electro-spark machining (EM), which is efficient, convenient, green and non-polluting, as well as customizable. The fabricated copper-molybdenum bimetallic oxide (MoCuOx) device showed good electrochemical performance under the electrode system. It provided a high areal capacity of 50.2 mF cm−2 (scan rate: 2 mV s−1) with outstanding cycling retention of 94.9% even after 2000 cycles. This work opens a new window for fabricating bimetallic oxide materials in an efficient, environmental and customizable way for various electronics applications.

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Wan, Xiaokang, Dashun Lu, Xianyun Wang, Gezhong Liu, Yanming Fu, Chao Hu, Nai Rong, Haitao Wang e Zude Cheng. "Enhanced Photoelectrochemical Water Oxidation on BiVO4 Photoanodes Functionalized by Bimetallic Dicyanamide Molecular Catalysts". Sustainability 15, n. 4 (8 febbraio 2023): 3129. http://dx.doi.org/10.3390/su15043129.

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Abstract (sommario):

A novel hybrid structure of bimetallic dicyanamide decorated BiVO4 is developed via a simple method to accelerate interfacial water oxidation kinetics. Two types of bimetallic dicyanamides, CoNi(dca)2 and CoFe(dca)2, are coated on BiVO4 photoanodes and are found to exhibit far more enhanced PEC performance than Co(dca)2 or Ni(dca)2 as cocatalysts. The successful deposition of metal dicyanamides on BiVO4 photoanodes is confirmed by physical characterizations including X-ray photoelectron spectroscopy (XPS). The optimized Co0.9Ni0.1(dca)2/BiVO4 photoanode exhibits the highest photocurrent density of 2.58 mA/cm2 at 1.23 V vs. RHE under 100 mW/cm2 AM 1.5 G irradiation, which is 2.5 times that of bare BiVO4. The substantial enhancement of PEC performance can be ascribed to the advantageous interfacial charge transfer and improved charge injection efficiencies. This work presents a feasible strategy using different types of bimetallic dicyanamides to design a modified BiVO4-based photoanode system for enhanced water oxidation efficiency.

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Jain, R., A. K. Rai e R. C. Mehrotra. "Bimetallic Alkoxides of Nickel(II) with Niobium(V) and Tantalum(V)". Zeitschrift für Naturforschung B 40, n. 10 (1 ottobre 1985): 1371–76. http://dx.doi.org/10.1515/znb-1985-1022.

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Abstract (sommario):

A new class of bimetallic isopropoxides of nickel(II) with niobium and tantalum with the general formula, Ni[M(OPri)6]2, (where M = Nb or Ta) have been synthesized by the reaction of nickel chloride isopropanolate, NiCl2·ϰPriOH, with potassium hexaisopropoxy metalates, KM(OPri)6, (M = Nb or Ta) in the molar ratio 1:2. These derivatives have been characterized by elemental analyses, molecular weight determinations, infrared and visible reflectance spectroscopy in addition to magnetic susceptibility measurements. Alcohol interchange reactions of these bimetallic alkoxides have also been studied. On the basis of above studies, an octahedral geometry has been assigned to Ni(II) in primary bimetallic alkoxides while in secondary derivatives, it appears that there exists an equilibrium between octahedral and tetrahedral forms.

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Nguyen Thi Tuyet, Mai, Hoai Hoang Thi Thu, Huy Nguyen Le, Hoai Tran Thanh e Hai Phan Van. "Synthesis of bimetallic Ag-Au nanoparticles for surface-enhanced Raman scattering spectroscopy". Vietnam Journal of Catalysis and Adsorption 11, n. 4 (11 dicembre 2022): 12–17. http://dx.doi.org/10.51316/jca.2022.063.

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In this report, bimetallic Au-Ag nanoparticles were successfully prepared by a chemical strategy using binary reduction agents. The metal ratio in bimetallic nanoparticles can be easily tuned by controlling the metal precursor ratio. Using Rhodamine as a probe molecule, we investigated the surface-enhanced Raman scattering (SERS) activity of synthesized bimetallic Au-Ag nanoparticles. The results demonstrate that our materials allow to enhance about 2×106 times the Raman signal of Rhodamine. Hence, the combination of unique features of two plasmonic metals opens up exciting prospects for the design of an ultra-sensitive sensor based on SERS.

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Kim, Whi Dong, Jung Min Park, Ji Young Ahn e Soo Hyung Kim. "Gas-Phase Growth of Heterostructures of Carbon Nanotubes and Bimetallic Nanowires". Journal of Nanomaterials 2011 (2011): 1–7. http://dx.doi.org/10.1155/2011/736219.

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Abstract (sommario):

A simple, inexpensive, and viable method for growing multiple heterostructured carbon nanotubes (CNTs) over the entire surface of Ni-Al bimetallic nanowires (NWs) in the gas phase was developed. Polymer-templated bimetallic nitrate NWs were produced by electrospinning in the first step, and subsequent calcination resulted in the formation of bimetallic oxide NWs by thermal decomposition. In the second step, free-floating bimetallic NWs were produced by spray pyrolysis in an environment containing hydrogen gas as a reducing gas. These NWs were continuously introduced into a thermal CVD reactor in order to grow CNTs in the gas phase. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectrometry analyses revealed that the catalytic Ni sites exposed in the non-catalytic Al matrix over the entire surface of the bimetallic NWs were seeded to radially grow highly graphitized CNTs, which resembled “foxtail” structures. The grown CNTs were found to have a relatively uniform diameter of approximately10±2 nm and 10 to 15 walls with a hollow core. The average length of the gas-phase-grown CNTs can be controlled between 100 and 1000 nm by adjusting the residence time of the free-floating bimetallic NWs in the thermal CVD reactor.

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Toshima, Naoki. "Core/shell-structured bimetallic nanocluster catalysts for visible-light-induced electron transfer". Pure and Applied Chemistry 72, n. 1-2 (1 gennaio 2000): 317–25. http://dx.doi.org/10.1351/pac200072010317.

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Abstract (sommario):

It has been found that the bimetallic nanoclusters often have so-called core/shell structure if they are prepared by alcohol-reduction of two kinds of noble metal ions in the presence of a water-soluble polymer like poly(N-vinyl-2-pyrolidone)(PVP), and that the core/ shell structured bimetallic nanoclusters have much higher catalytic activity than the corresponding monometallic nanoclusters. Here, several kinds of monometallic and bimetallic nanoclusters are synthesized by the similar method, and the catalyses are measured. Thus, the colloidal dispersions of Au, Pt, Pd, Rh, and Ru monometallic, and Au/Pt, Au/Pd, Au/Rh, and Pt/Ru bimetallic nanoclusters were synthesized and applied as the catalysts for visible-light- induced hydrogen generation. The core/shell structures are analyzed mainly by UV–vis spectra. The rate of electron transfer from the methyl viologen cation radical to the metal nanoclusters is proportional to the hydrogen generation rate at the steady state. All the electrons accepted by the metal nanoclusters are used for the hydrogen generation. Both electron transfer and hydrogen generation rates increase when the bimetallic nanoclusters are used in place of the corresponding monometallic nanoclusters. The most active catalysts were Au/Rh and Pt/Ru bimetallic nanoclusters.

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Pino, Natalia, Jennifer Quinchia, Santiago Gómez, Juan F. Espinal, Alejandro Montoya e Diana López. "Selective heterogeneous hydrodeoxygenation of acetophenone over monometallic and bimetallic Pt–Co catalyst". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 379, n. 2209 (13 settembre 2021): 20200346. http://dx.doi.org/10.1098/rsta.2020.0346.

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Abstract (sommario):

The hydrodeoxygenation (HDO) of acetophenone was evaluated in liquid phase and gas phase over monometallic Pt/SiO 2 , Co/SiO 2 and bimetallic Pt–Co/SiO 2 catalysts. The influence of reaction time and loading of the catalyst were analysed by following the conversion and products selectivity. Phenylethanol, cyclohexylethanone and cyclohexylethanol are the main products of reaction using the Pt/SiO 2 catalyst. By contrast, ethylbenzene and phenylethanol are the only products formed on the Co/SiO 2 and Pt–Co/SiO 2 catalysts. The bimetallic catalyst is more stable as a function of time and more active towards the HDO process than the monometallic systems. The presence of an organic solvent showed only minor changes in product yields with no effect on the product speciation. Periodic density functional theory analysis indicates a stronger interaction between the carbonyl group of acetophenone with Co than with Pt sites of the mono and bimetallic systems, indicating a key activity of oxophilic sites towards improved selectivity to deoxygenated products. This article is part of the theme issue ‘Bio-derived and bioinspired sustainable advanced materials for emerging technologies (part 2)’.

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Rashid, Hera, e P. V. Nidheesh. "Degradation of Textile Dye by Bimetallic Oxide Activated Peroxymonosulphate Process". Catalysts 13, n. 1 (13 gennaio 2023): 195. http://dx.doi.org/10.3390/catal13010195.

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Abstract (sommario):

The sulphate radical based advanced oxidation processes (AOPs) are highly in demand these days, owing to their numerous advantages. Herein, the Fe-Mn bimetallic oxide particle was used to activate peroxymonosulphate (PMS) for Rhodamine B (RhB) degradation. Three bimetallic catalysts were synthesized via the chemical precipitation method with different concentrations of metals; Fe-Mn (1:1), Fe-Mn (1:2) and Fe-Mn (2:1). The best performance was shown by Fe-Mn (2:1) system at optimized conditions; 96% of RhB was removed at optimized conditions. Scavenging experiments displayed the clear dominance of hydroxyl radical in pH 3, while sulphate radical was present in a large amount at pH 7 and 10. The monometallic Fe and Mn oxides were also synthesized to confirm the synergistic effect that was present in the bimetallic oxide system. The application of optimized condition in real textile wastewater was conducted, which revealed the system works efficiently at high concentrations of PMS and catalyst dosage.

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Goodwin, Vituruch, Phanwatsa Amnaphiang, Pimpreeya Thungngern, Kong Kah Shin, Parncheewa Udomsap e Nuwong Chollacoop. "Zeolite Supported Bimetallic Catalyst System: The Effect of Metal Loading for Catalytic Pyrolysis of Jatropha Residue". Key Engineering Materials 751 (agosto 2017): 494–99. http://dx.doi.org/10.4028/www.scientific.net/kem.751.494.

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Two transition metals were loaded on H-ZSM-5 zeolite to produce bimetallic zeolite supported catalysts for catalytic pyrolysis reaction. Ni and Co metal were loaded on H-ZSM-5 via wet impregnation method. The loading sequence was applied using one-step and two-step loading method. The different loading sequence affect surface properties of catalyst and catalytic activity in pyrolysis reaction. The bimetallic catalysts were prepared at Ni+Co metal loading content of 10+10 wt% (Ni:Co=1:1) to 10+20 wt% (Ni:Co=1:2 or 2:1). All bimetallic catalysts supported on H-ZSM-5 were calcined and characterized by X-ray Diffraction (XRD), Surface area analysis (BET) and Temperature Programmed Desorption of ammonia (NH3-TPD). The XRD patterns of bimetallic zeolite supported catalysts revealed that loading of two metals at high content affect crystalline structural of ZSM-5 support. All XRD patterns illustrated peaks characteristic of ZSM-5, cobalt oxide and nickel oxide. The NH3-TPD results showed number of acid sites of the catalyst which revealed that the acid sites of ZSM-5 support was weakened with transition metal added. The two-step loading of 10+20 wt% metals on ZSM-5 reduced the peak intensities of NH3 desorption due to the metal particles aggregate on acid sites of ZSM-5. The two-step 10+20 wt% bimetallic catalysts has the lowest surface acidity, followed by the one-step 10+20 wt%, the two-step 10+10 wt% and the one-step 10+10 wt% bimetallic catalysts, respectively. Jatropha residue was used for catalytic pyrolysis study. Jatropha residue and bimetallic catalyst was pyrolyzed at 500 °C in a pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The product vapor was analyzed by GC/MS for the different groups of organic products such as fatty acid, aldehydes, ketones, aliphatic hydrocarbons, aromatic hydrocarbons and nitrogen compounds. The product from catalytic pyrolysis of jatropha residue with bimetallic zeolite supported catalysts enhance deoxygenation reaction that resulted in high aliphatic and aromatic hydrocarbons product. The one-step loading at ratio Ni:Co = 1:1 (10+10 wt%) gave the highest hydrocarbons product yield at 57.81%.

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Malinga, Thoko, Tukayi Kudanga e Londiwe Simphiwe Mbatha. "Stealth doxorubicin conjugated bimetallic selenium/silver nanoparticles for targeted cervical cancer therapy". Advances in Natural Sciences: Nanoscience and Nanotechnology 12, n. 4 (1 dicembre 2021): 045006. http://dx.doi.org/10.1088/2043-6262/ac389c.

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Abstract Bimetallic nanosized delivery systems are attracting a lot of research interest as alternatives to monometallic delivery systems. This study evaluated the ability of bimetallic selenium silver chitosan pegylated folic acid targeted nanoparticles (SeAgChPEGFA NPs) to deliver doxorubicin (DOX) in cervical cancer cells. Comparison studies using monometallic selenium chitosan pegylated folic acid (SeChPEGFA NPs) targeted NPs and free DOX were also conducted. The prepared NPs and their drug nanocomplexes were characterised morphologically and physico-chemically. Drug binding and releasing studies were conducted under a simulated environment in vitro. The cytotoxicity and apoptosis studies were studied using the 3-[(4, 5-dimethylthiazol-2-yl)−2, 5-diphenyl tetrazolium bromide] (MTT) assay and the dual dye staining. The findings revealed that the bimetallic SeAgChPEGFA NPs displayed better colloidal stability, superior physico-chemical qualities, and higher binding abilities in comparison with monometallic SeChPEGFA NPs. In addition, the SeAgChPEGFA NPs showed the pH-triggered controlled drug release and cell-specific cytotoxicity. These findings suggest that the bimetallic NPs are superior delivery systems when compared to their monometallic NPs and free drug counterparts, thus, setting a platform for further in vivo examination.

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Pham, Hung Tan, Devashis Majumdar, Jerzy Leszczynski e Minh Tho Nguyen. "4d and 5d bimetal doped tubular silicon clusters Si12M2 with M = Nb, Ta, Mo and W: a bimetallic configuration model". Physical Chemistry Chemical Physics 19, n. 4 (2017): 3115–24. http://dx.doi.org/10.1039/c6cp05964c.

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Abstract (sommario):

M₂Si₁₂ clusters are found in a bimetallic tubular structure where one metal atom is located in the central region of a (6/6) tube, and the other is capped outside to a hexagonal face. A bimetallic configuration containing 11 MOs, partially or fully occupied by up to 22 electrons, was established to interpret their stability.

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Jiang, Jianbo, Chenyang Huang, Huiyong Ban e Letian Hai. "High-Cycle Fatigue Properties of Titanium-Clad Bimetallic Steel with Different Interfacial Conditions". Buildings 13, n. 3 (14 marzo 2023): 758. http://dx.doi.org/10.3390/buildings13030758.

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Titanium-clad (TC) bimetallic steel is an advanced composite steel consisting of metallurgically bonded titanium alloy and structural steel. This paper compared the high-cycle fatigue properties of three types of TC bimetallic steels, including two hot-rolled bonding types with different bonding strengths and an explosion-bonded type. The three types of TC bimetallic steels were all manufactured from TA2 titanium alloy as the cladding metal and Q355B structural steel as the substrate metal, of which the thicknesses are 2 mm and 8 mm, respectively. Based on the comparison results, the qualitative relationship between the bonding interface strength and the manufacturing methods with the basic mechanical and high-cycle fatigue properties was obtained. It was found that the different manufacturing methods and the bonding degree of the two component metals resulted in the different nonlinear yield plateau in the TC bimetallic steel. The high bonding strength seems to affect the failure mode of the tensile coupons. The bonding interface shear strength only slightly affects the tensile performance, which exhibits visible effects only when the test strain reaches the fractured state. In addition, three failure modes in total were found in the high-cycle fatigue tests for the three types of TC bimetallic steel. The manufacturing methods and the bonding interface strength significantly affect the fatigue phenomena of the TC bimetallic steel. The hot-rolled bonding TC bimetallic steel with high bonding strength has a 10% improvement in fatigue performance than the one with low bonding strength. Despite this, the manufacturing methods significantly affect the fatigue ratio, while the influence of the bonding strength on the high cycle fatigue performance is limited. The research outcomes can provide reference for the selection of different manufacturing methods and interfacial conditions for the use of TC bimetallic steel in structural engineering.

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Prakasam, Thirumurugan, Matteo Lusi, Elisa Nauha, John-Carl Olsen, Mohamadou Sy, Carlos Platas-Iglesias, Loïc J. Charbonnière e Ali Trabolsi. "Dynamic stereoisomerization in inherently chiral bimetallic [2]catenanes". Chemical Communications 51, n. 27 (2015): 5840–43. http://dx.doi.org/10.1039/c4cc07392d.

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Abstract (sommario):

Stereoisomerization and the unprecedented phenomenon of metal translocation in the absence of redox processes were probed in two inherently chiral bimetallic [2]catenanes by using a combination of variable-temperature ¹H NMR and CD spectroscopies, X-ray crystallography, and DFT calculations.

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Dowling, Carolyn, Danielle R. Dinsdale e Martin T. Lemaire. "Preparation, electrochemical behavior, and variable-temperature magnetic properties of Co(3,5-DBSQ)2 complexes of imidazole- or pyrazole-substituted ligands". Canadian Journal of Chemistry 93, n. 7 (luglio 2015): 769–74. http://dx.doi.org/10.1139/cjc-2014-0583.

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Abstract (sommario):

Herein we describe the preparation of four new Co(3,5-DBSQ)2 containing known 2-(2-pyridyl)benzimidazole 1, 2,2′-bisbenzimidazole 2, or 2,2-(1H-pyrazole-3,5-diyl)dipyridine 3. We investigate the electronic and variable-temperature magnetic susceptibility properties of these complexes. Complexes containing 2 and 3 are bimetallic and variable-temperature magnetic susceptibility data suggest observation of a stable intermediate (high-spin and low-spin) state for the bimetallic complex with 3, which does undergo valence tautomerism. Complexes 4–6 containing imidazole-based ligands 1 and 2 feature high-spin ground states and no valence tautomerism is observed in these materials. This experimental finding is corroborated with density functional theory calculations, which support the existence of a stable high-spin ground state in these complexes.

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Datta, Amitabha, Samiran Mitra e Georgina Rosair. "Synthesis, Characterisation and Structural Studies of [Zn(phen)3][Fe(CN)5(NO)]·2H2O·0.25MeOH and [(bipy)2(H2O)Zn(μ-NC)Fe(CN)4(NO)]·0.5H2O". Zeitschrift für Naturforschung B 58, n. 9 (1 settembre 2003): 916–21. http://dx.doi.org/10.1515/znb-2003-0913.

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Abstract (sommario):

Two new bimetallic complexes [Zn(phen)3][Fe(CN)5(NO)] · 2 H2O · 0.25 MeOH, (1) and [(bipy)2(H2O)Zn(μ-NC)Fe(CN)4(NO)] · 0.5 H2O, (2), have been isolated (where phen = 1,10-phenanthroline and bipy = bipyridyl) and characterised by X-ray crystallography [as the 2 H2O · 0.25 CH3OH solvate for (1) and hemihydrate for (2)] infrared spectroscopy and thermogravimetric analysis. Substitution of phenanthroline for bipyridyl resulted in a cyano-bridged bimetallic species rather than two discrete mononuclear metal complexes. The bond angles of Fe-N-O were shown to be practically linear for both 1 [179.2(7)°] and 2 [178.3(3)°], and the Zn atoms have distorted octahedral geometry. The solvent molecules in both crystal lattices take part in forming hydrogen-bonded networks.

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Kwon, Soonchul, Dong Jin Ham e Seung Geol Lee. "Enhanced H2 dissociative phenomena of Pt–Ir electrocatalysts for PEMFCs: an integrated experimental and theoretical study". RSC Advances 5, n. 68 (2015): 54941–46. http://dx.doi.org/10.1039/c5ra07228j.

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Zhang, Yuan, Metini Janyasupab, Chen-Wei Liu, Po-Yuan Lin, Kuan-Wen Wang, Jiaqiang Xu e Chung-Chiun Liu. "Improvement of Amperometric Biosensor Performance for H2O2Detection based on Bimetallic PtM (M = Ru, Au, and Ir) Nanoparticles". International Journal of Electrochemistry 2012 (2012): 1–8. http://dx.doi.org/10.1155/2012/410846.

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Abstract (sommario):

Novel bimetallic nanoparticles have been synthesized via rapid microwave irradiation, leading to an improved sensitivity and a highly anti-interference property for amperometric biosensor in H2O2detection. The material characterizations were performed by TEM, XRD, and EDX, which show the bimetallic formation of Pt-based catalysts and well-dispersed nanoparticles of 2–5 nm. The sensitivities for the detection of H2O2of PtRu, PtAu, and PtIr as the biosensor working electrode catalysts are 539.01 (R2=0.99), 415.46 (R2=0.99), and 404.52 (R2=0.97) μA mM−1 cm-2, respectively, nearly twice higher than the pure Pt catalyst (221.77 μA mM−1 cm−2,R2=0.98), at a low applied potential of +0.25 V versus Ag/AgCl. Furthermore, Pt-Ru and Pt-Ir show a highly sensitive response and a promising anti-interference capability to ascorbic acid, a major interferent, by reducing the interferent current as low as 7-8% significantly lower than that of Pt (30% change). The enhancement of both sensitivity and selectivity in the bimetallic catalysts can be found practical applications in biosensing.

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Shi, Li-Mei, Jing-Xiong Pan, Bo Zhou e Xiaoqing Jiang. "A new bifunctional electrochemical sensor for hydrogen peroxide and nitrite based on a bimetallic metalloporphyrinic framework". Journal of Materials Chemistry B 3, n. 48 (2015): 9340–48. http://dx.doi.org/10.1039/c5tb01361e.

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Drăghiceanu, Oana-Alexandra, Anca Nicoleta Șuțan, Codruța Mihaela Dobrescu, Nicoleta Doruța Bătut-Andrei, Liliana Cristina Soare e Carmen Mihaela Topală. "CHARACTERIZATION IN TERMS OF COMPOSITION AND PHYTOTOXICITY OF AQUEOUS SPORES EXTRACT". Current Trends in Natural Sciences 10, n. 20 (31 dicembre 2021): 53–60. http://dx.doi.org/10.47068/ctns.2021.v10i20.008.

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In this study, we used aqueous extracts of fern spores and solution of AgNO3 and HAuCl4 for the synthesis of bimetallic nanoparticles Au:Ag in different proportions: 1:1 and 1:10. The spores used come from 2 species of ferns: Asplenium scolopendrium and Dryopteris filix-mas. For the characterization of the extracts with or without bimetallic nanoparticles we applied Fourier transform infrared spectroscopy (FT-IR). Phytotoxicity was tested using Pisum sativum seeds. Each extract was tested in 2 dilutions: 1:10 (D10) and 1:100 (D100). The parameters, which we determinate were the root and stem growth and fresh biomass. Root growth was stimulated in variants with Asplenium scolopendrium extract: without nanoparticles both dilution and with Au:Ag nanoparticles 1:10 D10. The highest values obtained for the stem were at D10 at the variants with Asplenium scolopendrium extract with or without bimetallic nanoparticles. The influence of extracts on fresh biomass was smaller than on the growth of root and stem.

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Piccolo, Oreste, Iztok Arčon, Gangadhar Das, Giuliana Aquilanti, Andrea Prai, Stefano Paganelli, Manuela Facchin e Valentina Beghetto. "Synthesis of Helional by Hydrodechlorination Reaction in the Presence of Mono- and Bimetallic Catalysts Supported on Alumina". Catalysts 14, n. 4 (12 aprile 2024): 255. http://dx.doi.org/10.3390/catal14040255.

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Abstract (sommario):

Hydrodechlorination reaction of 3-(benzo-1,3-dioxol-5-yl)-3-chloro-2-methylacrylaldehyde in the presence of different low metal content heterogeneous mono- or bimetallic catalysts was tested for the synthesis of the fragrance Helional® (3-[3,4-methylendioxyphenyl]-2-methyl-propionaldehyde). In particular, mono Pd/Al2O3, Rh/Al2O3 or bimetallic Pd-Cu/Al2O3, Rh-Cu/Al2O3 catalysts were tested in different reaction conditions from which it emerged that mono-Rh/Al2O3 was the best performing catalyst, allowing achievement of 100% substrate conversion and 99% selectivity towards Helional® in 24 h at 80 °C, p(H2) 1.0 MPa in the presence of a base. To establish correlations between atomic structure and catalytic activity, catalysts were characterized by Cu, Rh and Pd K-edge XANES, EXAFS analysis. These characterizations allowed verification that the formation of Pd-Cu alloys and the presence of Cu oxide/hydroxide species on the surface of the Al2O3 support are responsible for the very low catalytic efficiency of bimetallic species tested.

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He, Zhenhong, Qingli Qian, Zhaofu Zhang, Qinglei Meng, Huacong Zhou, Zhiwei Jiang e Buxing Han. "Synthesis of higher alcohols from CO 2 hydrogenation over a PtRu/Fe 2 O 3 catalyst under supercritical condition". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 373, n. 2057 (28 dicembre 2015): 20150006. http://dx.doi.org/10.1098/rsta.2015.0006.

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Abstract (sommario):

Hydrogenation of CO 2 to alcohols is of great importance, especially when producing higher alcohols. In this work, we synthesized heterogeneous PtRu/Fe 2 O 3 , in which the Pt and Ru bimetallic catalysts were supported on Fe 2 O 3 . The catalyst was used to catalyse CO 2 hydrogenation to alcohols. It was demonstrated that the activity and selectivity could be tuned by the bimetallic composition, and the catalyst with a Pt to Ru molar ratio of 1:2 (Pt 1 Ru 2 /Fe 2 O 3 ) had high activity and selectivity at 200°C, which is very low for heterogeneous hydrogenation of CO 2 to produce higher alcohols. The conversion and the selectivity increased with increasing pressures of CO 2 and/or H 2 . The catalyst could be reused at least five times without any obvious change in activity or selectivity.

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Llorca-Isern, Núria, Ana Maria Escobar, Antoni Roca e Jose María Cabrera. "Equal Channel Angular Pressing of Cu-Al Bimetallic Rod". Materials Science Forum 706-709 (gennaio 2012): 1811–16. http://dx.doi.org/10.4028/www.scientific.net/msf.706-709.1811.

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Abstract (sommario):

Coextrusion and corolling are the major processes to produce bimetallic rods, tubes and wires, the objective being to perform clad metals, bimetallic joints or seals. The aim of the present work is to produce bimetallic rods showing an ultrafine grained microstructure with enhanced properties. Bimetallic Cu-Al rods were deformed by equal channel angular pressing (ECAP) in order to study their microstructure. ECAP is an interesting process for producing bulk materials with refined microstructure and, consequently, changes in physical, chemical and mechanical properties can be observed. Higher shear strength and dimensional stability are among the advantages of this process. A comparative experimental study of pure commercial copper with cylindrical inner aluminium rods of different diameters processed by one-pass equal channel angular pressing has been carried out. The ECAP die used in this research was a 90º 2-channels intersecting angle. Electron backscattered (EBSD) and X-ray diffraction techniques were used for microstructure characterization (deformation, grain fragmentation and microstrain evaluation) at the interfaces and away from them. It was found that the microstructure in the ECAP deformed Cu-Al bimetallic rods was influenced by the dimensions of the aluminium inner rod. In fact, the microstructure appeared to be much more elongated and refined in the samples containing smaller diameter aluminium rods.

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46

Zhang, Xiaolong, Fengwang Li, Ying Zhang, Alan M. Bond e Jie Zhang. "Stannate derived bimetallic nanoparticles for electrocatalytic CO2 reduction". Journal of Materials Chemistry A 6, n. 17 (2018): 7851–58. http://dx.doi.org/10.1039/c8ta02429d.

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47

Depauw, Hannes, Irena Nevjestić, Guangbo Wang, Karen Leus, Freddy Callens, Els De Canck, Klaartje De Buysser, Henk Vrielinck e Pascal Van Der Voort. "Discovery of a novel, large pore phase in a bimetallic Al/V metal–organic framework". Journal of Materials Chemistry A 5, n. 47 (2017): 24580–84. http://dx.doi.org/10.1039/c7ta08103k.

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48

Ridenour, J. August, e Christopher L. Cahill. "Nine isomorphous lanthanide–uranyl f–f bimetallic materials with 2-thiophenecarboxylic acid and terpyridine: structure and concomitant luminescent properties". CrystEngComm 20, n. 34 (2018): 4997–5011. http://dx.doi.org/10.1039/c8ce00811f.

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49

Kim, Young-hee, Yvonne M. McKinnes, Paul A. Cooke, Robert Greatrex, John D. Kennedy e Mark Thornton-Pett. "Metallaborane Reaction Chemistry. Part 7. B-Frame Supported Bimetallics: Ligand-to-β-Metal Organometallic Interaction in Dimetallaboranes and an Interesting Ligand Displacement Cascade". Collection of Czechoslovak Chemical Communications 64, n. 6 (1999): 938–46. http://dx.doi.org/10.1135/cccc19990938.

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Abstract (sommario):

Reaction of [PtCl2(PMe2Ph)2] with [(PMe2Ph)2PtB10H12] generates [(PMe2Ph)2-μ-η1(Pt)- η1-(Pt')-{PMe2(C6H4)}-closo-Pt2B10H9(PMe2Ph)] in which the phenyl group of a phosphine ligand on one platinum atom exhibits ortho-cyclometallation to the second metal atom, whereas reaction of PPh3 with [(PMe2Ph)2PtB9H9Ru(pcym)] generates [(PMe2Ph)2-μ-η6(Ru)- η1(Pt)-(C6H5PPh2)-closo-PtRuB9H9] in which the phenyl group of a phosphine ligand on the platinum atom exhibits tridentate η6 coordination to the second metal atom.

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50

Shiraishi, Yukihide, Daisuke Ikenaga e Naoki Toshima. "Preparation and Catalysis of Inverted Core/Shell Structured Pd/Au Bimetallic Nanoparticles". Australian Journal of Chemistry 56, n. 10 (2003): 1025. http://dx.doi.org/10.1071/ch03051.

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Abstract (sommario):

Reduction of two different precious metal ions by refluxing in ethanol/water in the presence of poly(N-vinyl-2-pyrrolidone) (PVP) gave a colloidal dispersion of core/shell structured bimetallic nanoparticles. In the case of Pd and Au ions, for example, the colloidal dispersions of bimetallic nanoparticles with a Au core/Pd shell structure are produced. In contrast, it is difficult to synthesize bimetallic nanoparticles with the inverted core/shell (in this case, Pd core/Au shell) structure. Here the sacrificial hydrogen strategy has been used to construct the inverted core/shell structure, where the colloidal dispersions of Pd cores are treated with hydrogen and then the solution of the second element, Au ions, is slowly added to the dispersions. This novel method, developed by us, gave the inverted core/shell structured bimetallic nanoparticles. The Pd core/Au shell structure has been confirmed by FT-IR spectra of adsorbed carbon monoxide. The hydrogenation of methyl acrylate catalyzed by the nanoparticles before and after heat treatment was investigated as well.

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