GRATZEL and R. VÖLKL, Metall. Mater. Trans., 2005, 36A, 681–689 Pt-base alloys (1) with various contents of Al, Cr and Ni were arc melted. Solution heat treatments at 1450oC followed by water quenching gave single phase alloys. Ageing at 1000oC caused the precipitation of L12 ordered particles. (1), comprising (in at.%): 11 Al; 3 Cr; 6 Ni and balance Pt, had cuboidal precipitates with edge leng...

We describe the synthesis, magnetism and structure of CoPtCrB alloys with Pt concentrations from 10 43 %. The Cr concentration in the alloys was 15-17 % and the B concentration was 9-11 %. The magnetic anisotropy and coercivity increase with increasing Pt up to M 30%, plateau at M 35,000 Oe and w 6000 Oe, respectively, and then decrease. Transmission electron microscopy results show the media f...

in this study ptfeco ternary alloys nanoparticles of three dimentional (3d) rhombus shapes dispersed on graphene nanosheets (ptfeco/gr) were successfully prepared and studied as electrocatalysts for oxygen reduction reaction (orr) in polymer-electrolyte fuel cells. a combination of analytical techniques including powder x-ray diffraction, x-ray photoelectron spectra, inductively coupled plasma-...

A simple and general dealloying method is employed to fabricate nanoporous Au/Pt alloys with pre-determined alloy compositions. Structural characterization by electron microscopes demonstrates that selective etching of Cu from Au/Pt/Cu alloy precursors results in the formation of three-dimensional bicontinuous porous network structures with uniform pores and ligaments less than 10 nm. X-Ray pho...

Better oxygen reduction catalysts are needed to improve the efficiency and lower the cost of fuel cells. Metal nanoparticles are good candidates because their catalytic properties can differ from bulk metals. Using density functional theory calculations, we studied the geometric relaxation of metal nanoparticles upon oxygen binding. Because bound oxygen species are intermediates in the oxygen r...

Improving the efficiency of electrocatalytic reduction of oxygen represents one of the main challenges for the development of renewable energy technologies. Here, we report the systematic evaluation of Pt-ternary alloys (Pt3(MN)1 with M, N = Fe, Co, or Ni) as electrocatalysts for the oxygen reduction reaction (ORR). We first studied the ternary systems on extended surfaces of polycrystalline th...

0021-9517/$ see front matter 2010 Elsevier Inc. A doi:10.1016/j.jcat.2010.06.017 * Corresponding author. Fax: +1 510 642 4778. E-mail address: [email protected] (A.T. Bel A novel approach is described for preparing Ga-promoted Pt particles for the dehydrogenation of light alkanes to alkenes. The modifying element, Ga, was introduced by transference from the support, a calcined Mg(Ga)(Al)O...

Scratching beneath the surface: Pt-M(3d)-Pt(111) (M(3d) = Co, Ni) bimetallic subsurface alloys have been designed to show the ligand effect tunes reactivity in oxygen and hydrogen adsorption systems. The platinum-oxygen bond order was investigated by oxygen atom projection in the occupied and unoccupied space using X-ray emission spectroscopy (XES) and X-ray absorption spectroscopy (XAS).

We report on a versatile approach for preparing on-substrate, self-standing and hollow-wall nanotubes (NTs) of Pt and PtRu-alloys. The method takes advantage of wet chemically processed ZnO-NTs that are used as sacrificial templates for electrodeposition. The electrocatalytic activity of these Pt-based NTs is exemplary demonstrated on the electro-oxidation of methanol.

Further advances in fuel cell technologies are hampered by kinetic limitations associated with the sluggish cathodic oxygen reduction reaction. We have investigated a range of different formulations of binary and ternary Pt, Pd and Au thin films as electrocatalysts for oxygen reduction. The most active binary thin films are near-surface alloys of Pt with subsurface Pd and certain PdAu and PtAu ...