Synthesis and structural studies of some selenoureas and their metal complexes

Molter, Anja; Rust, Jörg; Lehmann, Christian W.; Mohr, Fabian

doi:10.3998/ark.5550190.0012.602

Cited by 7 publications

(7 citation statements)

References 10 publications

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“…General procedures 1 H, 13 [45][46][47][48] All other chemicals and solvents (anhydrous grade) were sourced commercially and used as received. Reactions involving air-and moisture sensitive compounds were carried out under dry dinitrogen gas using standard Schlenk techniques.…”

Section: Methodsmentioning

confidence: 99%

Gold(iii) compounds containing a chelating, dicarbanionic ligand derived from 4,4′-di-tert-butylbiphenyl

et al. 2014

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An oligomeric gold(III) compound containing dicarbanionic chelating 4,4'-di-tert-butylbiphenyl was prepared via transmetallation using the corresponding organotin(IV) compound. The reactivity of the chloro-bridged oligomer with various species including neutral N-, P-, and C-donor ligands as well as monoanionic S- and Se-ligands was investigated. Some of the products were characterised by X-ray crystallography. The photophysical properties of two derivatives were studied.

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Section: Methodsmentioning

confidence: 99%

Gold(iii) compounds containing a chelating, dicarbanionic ligand derived from 4,4′-di-tert-butylbiphenyl

et al. 2014

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“…Thus we propose the synthesis of new carbonsupported ruthenium-selenium nitrogen chelated catalyst where one compound, namely selenourea, is used as the N and Se precursor. The inspiration came from literature where the ability of ruthenium to form the chelates with selenourea and thiourea was described (15,16). It has been recently revealed that selenium-modified metals like Co, Ir, Rh exhibit higher electroactivity in comparison to unmodified nanoparticles (5,(17)(18)(19).…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of New Non-Platinum Electrocatalysts for Oxygen Reduction

et al. 2013

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A new group of carbon-supported ruthenium-and iridium-based electrocatalysts for oxygen reduction reaction (ORR) was synthesized, using RuCl 3 or IrCl 3 and selenourea (as precursor of both Se and N). The heat treated catalysts (later abbreviated as RuSeN/C and IrSeN/C) were subjected to physical characterization, like X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Studies revealed changes in surface properties of Ru-and Ir-based catalysts. Catalytic performances of obtained catalysts were evaluated using Rotating Ring Disk Electrode (RRDE) in acid solution. The ORR activity and hydrogen peroxide generation on designed selenides were dependent on the ratio of metal and selenourea used in precursor blend and were separately characteristic for ruthenium and iridium. While RuSeN/C exhibited high ethanol tolerance, the ORR activity of IrSeN/C in the presence of ethanol depended on the amount of selenourea. CoSeN/C and FeSeN/C were also prepared and characterized as low-cost alternative catalysts.

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“…In the proposed approach, selenourea acts as a source of selenium and nitrogen capable of coordinatively binding to ruthenium ion. 12 Of importance is also the possibility of chemical linking with partially oxidized carbon supports through the formation of free amine groups. Both the relative contents of Ru and selenourea within the precursor blend and the annealing temperature should be optimized to get high electroactivity during the oxygen reduction reaction.…”

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confidence: 99%

Electrocatalytic Activity toward Oxygen Reduction of RuS_xN_yCatalysts Supported on Different Nanostructured Carbon Carriers

Dobrzeniecka¹,

Kulesza²

2013

ECS J. Solid State Sci. Technol.

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Ruthenium admixed or nanoparticles modified with mixed selenium and nitrogen overlayers (RuSe x N y ) were fabricated onto different carbon nanostructured supports (that include multiwalled carbon nanotubes, Vulcan and Norit) under analogous experimental conditions. It is apparent from X-ray measurements that both Vulcan and Norit supported RuSe x N y crystallites are characterized by the same type of crystallographic phases. Important parameters that influence electrocatalytic activity include the nature of functionalization of carbon support, in addition to its active surface area and morphology that affect distribution and size of active RuSe x N y centers. Despite the same loading of ruthenium (40 μg cm −2 ), diameters of RuSe x N y nanoparticles have somewhat differed and ranged from 2 to 6 nm, as it has been evident from transmission electron microscopy measurements. The systems have been evaluated with respect to oxygen reduction reaction in acid (0.5 M H 2 SO 4 ) medium using rotating ring disk voltammetry and impedance spectroscopy. Having in mind such parameters as the half-wave reduction potential, the electroreduction current density, the heterogenous rate constant, the percent formation of the hydrogen peroxide undesirable intermediate as well as the overall charge transfer resistance appearing during oxygen reduction, the RuSe x N y -based system utilizing functionalized Vulcan is characterized by the highest electrocatalytic activity.The unique textural and electronic properties of carbon materials have been explored with respect to the development of supports for catalytic systems, particularly of interest to the technology of low temperature of fuel cells. 1,2 Utilization of a carbon support allows better distribution of metal centers and leads to increase the electrochemically active area of the catalytic system. Physical properties of carbon supports influence electrochemical activity of dispersed metal nanoparticles. 3,4 Further, when the metal nanoparticles diameter decrease the electrochemically active area increase. 5 Among important features are good electrical conductivity, mechanical rigidity and chemical inertness of carbon supporrts. The porosity factor, which is determined by morphology of the catalyst support, is essential to provide efficient mass transport to the active centers. Uniform dispersion of metal centers and application of carbon supports of high surface area tend to facilitate transport of reactants (fuels). Activity of catalytic systems is also dependent on the nature of interactions between the support and catalytic centers that affect electronic properties of metal nanoparticles, their shape and, indirectly, the number of reactive sites. 6-8 Another important factor is the carbon support corrosion resistance which becomes truly problematic during long-term operation of catalytic systems particularly at temperatures higher than 100 • C. 9,10 In the present work, we comment on the importance of functionalization of three different carbon supports with respect to activit...

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Synthesis and structural studies of some selenoureas and their metal complexes

Cited by 7 publications

References 10 publications

Gold(iii) compounds containing a chelating, dicarbanionic ligand derived from 4,4′-di-tert-butylbiphenyl

Gold(iii) compounds containing a chelating, dicarbanionic ligand derived from 4,4′-di-tert-butylbiphenyl

Synthesis and Characterization of New Non-Platinum Electrocatalysts for Oxygen Reduction

Electrocatalytic Activity toward Oxygen Reduction of RuS_xN_yCatalysts Supported on Different Nanostructured Carbon Carriers

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Synthesis and structural studies of some selenoureas and their metal complexes

Cited by 7 publications

References 10 publications

Gold(iii) compounds containing a chelating, dicarbanionic ligand derived from 4,4′-di-tert-butylbiphenyl

Gold(iii) compounds containing a chelating, dicarbanionic ligand derived from 4,4′-di-tert-butylbiphenyl

Synthesis and Characterization of New Non-Platinum Electrocatalysts for Oxygen Reduction

Electrocatalytic Activity toward Oxygen Reduction of RuSxNyCatalysts Supported on Different Nanostructured Carbon Carriers

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Product

Resources

About

Electrocatalytic Activity toward Oxygen Reduction of RuS_xN_yCatalysts Supported on Different Nanostructured Carbon Carriers