Pt Skin Versus Pt Skeleton Structures of Pt3Sc as Electrocatalysts for Oxygen Reduction

Johansson, Tobias Peter; Ulrikkeholm, Elisabeth Therese; Fernández, Pedro Riesgo; Hansen, Heine Anton; Bandarenka, Aliaksandr S.; Nørskov, Jens K.; Stephens, Ifan E. L.; Chorkendorff, Ib

doi:10.1007/s11244-013-0179-y

Cited by 51 publications

(46 citation statements)

References 58 publications

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“…Recently, using a "hard templating" method based on galvanic replacement and the nanoscale Kirkendall effect, we and other groups synthesized hollow PtCo/C or PtNi/C nanoparticles to electrocatalyze the oxygen reduction reaction (ORR) in proton-exchange membrane fuel cells (PEMFCs) [3,4,[7][8][9]11]. Alloying Pt with a 3d transition metal such as Co, [12][13][14][15][16][17][18] Ni, [14,15,[19][20][21] Y, [22,23] Sc, [24] or Gd, [25] is a common way to tailor the chemisorption energies of oxygen-containing ORR intermediates via strain [26][27][28][29][30] and ligand [31][32][33] effects. This in turn affects the preexponential term of the Arrhenius equation and thus enhances the ORR rate.…”

Section: Introductionmentioning

confidence: 99%

Atomic-scale restructuring of hollow PtNi/C electrocatalysts during accelerated stress tests

et al. 2016

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Section: Introductionmentioning

confidence: 99%

Atomic-scale restructuring of hollow PtNi/C electrocatalysts during accelerated stress tests

et al. 2016

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“…22,23 However, extended stability tests indicate that further dealloying of the bulk, which occurs on the long term, destabilizes and deactivates these catalysts. 24,25 Recently, a new class of catalytic materials based on Pt and early transition metal such as Y or Sc, [26][27][28][29] or lanthanide metals such as La, Ce, Gd, also emerged. 3,30,31 The guiding idea is that the more negative heat of alloy formation of these materials, compared to that of Pt and late transition metals alloys, could prevent dealloying of the bulk, ultimately increasing the stability of Pt-skeleton structures.…”

Section: Introductionmentioning

confidence: 99%

Direct observation of the dealloying process of a platinum–yttrium nanoparticle fuel cell cathode and its oxygenated species during the oxygen reduction reaction

Malacrida

Casalongue

Masini

et al. 2015

Phys. Chem. Chem. Phys.

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Size-selected 9 nm PtxY nanoparticles have recently shown an outstanding catalytic activity for the oxygen reduction reaction, representing a promising cathode catalyst for proton exchange membrane fuel cells (PEMFCs). Studying their electrochemical dealloying is a fundamental step towards the understanding of both their activity and stability. Herein, size-selected 9 nm PtxY nanoparticles have been deposited on the cathode side of a PEMFC specifically designed for in situ ambient pressure X-ray photoelectron spectroscopy (APXPS). The dealloying mechanism was followed in situ for the first time. It proceeds through the progressive oxidation of alloyed Y atoms, soon leading to the accumulation of Y(3+) cations at the cathode. Acid leaching with sulfuric acid is capable of accelerating the dealloying process and removing these Y(3+) cations which might cause long term degradation of the membrane. The use of APXPS under near operating conditions allowed observing the population of oxygenated surface species as a function of the electrochemical potential. Similar to the case of pure Pt nanoparticles, non-hydrated hydroxide plays a key role in the ORR catalytic process.

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“…[39][40][41] In our laboratory we have taken a different approach, namely to study alloys of Pt and rare earths such as Y, Gd, Ce and La. 33,[42][43][44][45][46][47][48] These alloys have a particularly negative heat of formation, which should provide them with long term-kinetic stability against dealloying at the cathode of a fuel cell. Extended surfaces of Pt 3 Y and Pt 5 Gd show particularly high activity for oxygen reduction.…”

Section: Introductionmentioning

confidence: 99%

Exploring the phase space of time of flight mass selected Pt_xY nanoparticles

Masini

Hernández-Fernández

Deiana³

et al. 2014

Phys. Chem. Chem. Phys.

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Mass-selected nanoparticles can be conveniently produced using magnetron sputtering and aggregation techniques. However, numerous pitfalls can compromise the quality of the samples, e.g. double or triple mass production, dendritic structure formation or unpredicted particle composition. We stress the importance of transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and ion scattering spectroscopy (ISS) for verifying the morphology, size distribution and chemical composition of the nanoparticles. Furthermore, we correlate the morphology and the composition of the Pt x Y nanoparticles with their catalytic properties for the oxygen reduction reaction. Finally, we propose a completely general diagnostic method, which allows us to minimize the occurrence of undesired masses.

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Pt Skin Versus Pt Skeleton Structures of Pt3Sc as Electrocatalysts for Oxygen Reduction

Cited by 51 publications

References 58 publications

Atomic-scale restructuring of hollow PtNi/C electrocatalysts during accelerated stress tests

Atomic-scale restructuring of hollow PtNi/C electrocatalysts during accelerated stress tests

Direct observation of the dealloying process of a platinum–yttrium nanoparticle fuel cell cathode and its oxygenated species during the oxygen reduction reaction

Exploring the phase space of time of flight mass selected Pt_xY nanoparticles

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Pt Skin Versus Pt Skeleton Structures of Pt3Sc as Electrocatalysts for Oxygen Reduction

Cited by 51 publications

References 58 publications

Atomic-scale restructuring of hollow PtNi/C electrocatalysts during accelerated stress tests

Atomic-scale restructuring of hollow PtNi/C electrocatalysts during accelerated stress tests

Direct observation of the dealloying process of a platinum–yttrium nanoparticle fuel cell cathode and its oxygenated species during the oxygen reduction reaction

Exploring the phase space of time of flight mass selected PtxY nanoparticles

Contact Info

Product

Resources

About

Exploring the phase space of time of flight mass selected Pt_xY nanoparticles