The electrocatalysis of the oxygen reduction reaction (ORR) on five binary Pi alloys (PtCr/C, PtMn/C, PtFe/C, PtCo/C, and PtNi/C) supported on high surface area carbon in a proton exchange membrane fuel cell was investigated. All the alloy electrocatalysts exhibited a high degree of crystallinity with the primary phase of the type Pt3M (LI2 structure with fcc type lattice) and a secondary phase...

The current study investigated the unique combination of alloying (Pt with Cr) and Nafion stabilisation to reap the benefits of catalyst systems with enhanced catalytic activity and improved durability in PEMFCs. Pt–Cr alloy nanoparticles stabilised with Nafion were chosen in the current study owing to their higher stability in acidic and oxidising media at high temperatures compared to other P...

Herein, we report a novel polymerized-complex method for the preparation of Ni-Pd, Ni-Pt, and Cu-Pt alloys and Pt, Pd, Ag, Ni, and Cu nanoparticles. The grain sizes and crystalline phases of these nanoparticles can be controlled. These nanoparticles are obtained via the formation of a polymerized complex and release of reducing gases during N2-protected calcination.

The anomalous Hall effect (AHE) in L1(0)FePd(1-x)Pt(x) alloy films is studied both experimentally and theoretically. We find that the intrinsic contribution (σ(AH)(int)) to the AHE can be significantly increased, whereas the extrinsic side-jump contribution (σ(AH)(sj)) can be continuously reduced from being slightly larger than σ(AH)(int) in L1(0) FePd to being much smaller than σ(AH)(int) in L...

Inelastic nuclear resonant scattering spectra of Fe atoms were measured on crystalline alloys of Pt3 Fe that were chemically disordered, partially ordered, and L12 ordered. Phonon partial density of states curves for Fe were obtained from these spectra. Upon disordering, about 10% of the spectral intensity underwent a distinct shift from 25 to 19 meV. This change in optical modes accounted for ...

Herein, we report a one-step synthesis method for octahedral Pt-Ni-Co ternary catalysts with tunable compositions and fixed shapes. Impressively, the composition optimized octahedral PtNi0.55Co0.1/C demonstrated a significant improvement in ORR activity compared to those of previously reported Pt-Ni-Co alloy octahedra, showing an outstanding specific activity of 5.05 mA cm-2 and a mass activity...

Dealloyed Pt bimetallic core-shell catalysts derived from low-Pt bimetallic alloy nanoparticles (e.g, PtNi3 ) have recently shown unprecedented activity and stability on the cathodic oxygen reduction reaction (ORR) under realistic fuel cell conditions and become today's catalyst of choice for commercialization of automobile fuel cells. A critical step toward this breakthrough is to control thei...

Velocity of sound and thermal expansion measurements on Cr-Pt alloys in the concentration range up to 1.5 at.% Pt are reported. The existence of a triple point and a mixed magnetic state on the magnetic phase diagram is suggested. The magnetic phase diagram [I] of dilute Cr-Pt alloys contains a paramagnetic (P), an incommensurate (I) and a commensurate (C) spin density wave (SDW) phase. Rather ...

The aim of this research was to evaluate the effect of individual metallic elements within experimental Au-Pt-based metal-ceramic alloys on in vitro biocompatibility. A binary Au-10 at.% Pt alloy (AP10) was designed as a parent alloy. Six ternary AP10-X (X = In/Fe/Sn/Zn) alloys and four quaternary (AP10-In2)-Y (Y = Fe/Sn/Zn) with different compositions were cast into square plates with size 10X...

Pt-modified NiAl is widely used as a coating material in industry. In this study, the surface energies of NiAl with and without Pt are investigated using first-principles calculations. The presence of Pt in NiAl takes the surface electronic states to higher energies, resulting in an increased surface energy, which explains some of the beneficial effects of Pt on the oxidation resistance of NiAl...