Ruthenium alloys nanoparticles

Platinum, ruthenium and PtRu alloy nanoparticles, prepared by vacuum pyrolysis using Pt(acac)2 and Ru(acac)3 as precursors, were applied as anode catalysts for direct methanol oxidation . The nanoparticles, uniformly dispersed on multiwaUed carbon nanotubes, were all less than 3.0 nm in size and had a very narrow size distribution. The nanocomposite catalysts showed strong electrocatalytic activity for methanol oxidation, which can... 

Size Spherical gold/silver alloy nanoparticles, surrounded by a silica spacer shell, to which is attached a fluorescent ruthenium dye, have been studied. The... 

PtRu nanoparticles can be prepared by w/o reverse micro-emulsions of water/Triton X-lOO/propanol-2/cyclo-hexane [105]. The bimetallic nanoparticles were characterized by XPS and other techniques. The XPS analysis revealed the presence of Pt and Ru metal as well as some oxide of ruthenium. Hills et al. [169] studied preparation of Pt/Ru bimetallic nanoparticles via a seeded reductive condensation of one metal precursor onto pre-supported nanoparticles of a second metal. XPS and other analytical data indicated that the preparation method provided fully alloyed bimetallic nanoparticles instead of core/shell structure. AgAu and AuCu bimetallic nanoparticles of various compositions with diameters ca. 3 nm, prepared in chloroform, exhibited characteristic XPS spectra of alloy structures [84]. 

E25.17 Electrocatalysts are compounds that are capable of reducing the kinetic barrier for electrochemical reactions (barrier known as overpotential). While platinum is the most efficient electrocatalyst for accelerating oxygen reduction at the fuel cell cathode, it is expensive (recall Section 25.18 Electrocatalysis). Current research is focused on the efficiency of a platinum monolayer by placing it on a stable metal or alloy clusters your book mentions the use of the alloy PtsN. An example would be a platinum monolayer fuel-cell anode electrocatalyst, which consists of ruthenium nanoparticles with a sub-monolayer of platinum. Other areas of research include using tethered metalloporphyrin complexes for oxygen activation and subsequent reduction. 

In summary, the organometallic approach is also efficient to prepare bimetallic nanoparticles. By precisely selecting the reaction conditions (precursor, stabilizer, reactant), we could access to ruthenium-based bimetallic nanoparticles displaying a controlled chemical order, i.e. alloy, core-shell, or even nanoparticles decorated with a second metal such as platinum, iron, or tin. These nanoparticles, which display different surface properties, can pave the way towards synergetic and selective catalytic performances. 

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