Reversibility of Pt-Skin and Pt-Skeleton Nanostructures in Acidic Media

Durst, Julien; López‐Haro, Miguel; Dubau, Laëtitia; Chatenet, Marian; Soldo-Olivier, Yvonne; Guétaz, Laure; Bayle–Guillemaud, Pascale; Maillard, Frédéric

doi:10.1021/jz4025707

Cited by 49 publications

(49 citation statements)

References 46 publications

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“…After 1000 cycles, the peak current densities of MOR are 77, 48, 8.4, 51, and 10 mA cm À2 for 3D Pt 3 Co NWA, 3D Pt NWA, Pt/CB, PtRu/CB, and Pt black, which are about 82 %, 80 %, 33 %, 55 %, and 63 % of their initial values, respectively (Figures 3 d, S15, and S17). [53][54][55] After the ADT test, XPS peak positions of Pt 3 Co NWA are 71.4 eV for Pt 4f 7/2 and 778.2 eV for Co 2p 3/2 , which are close to the initial ones (71.4 and 778.1 eV, respectively; Figures S12 and S19). Furthermore, the final current density of the 3D Pt 3 Co NWA in chronoamperometric measurements is higher than those of PtRu/CB and Pt/CB, indicating that 3D Pt 3 Co NWA is more active and stable than PtRu/CB and Pt/CB (Figures 4 and S18b).…”

Section: Methodssupporting

confidence: 51%

One‐Pot Synthesis of Pt–Co Alloy Nanowire Assemblies with Tunable Composition and Enhanced Electrocatalytic Properties

et al. 2015

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Three-dimensional (3D) Pt-based alloy nanostructures composed of one-dimensional (1D) nanowires/nanorods have recently attracted significant interest as electrocatalysts. In this work, we report an effective solvothermal method for the direct preparation of 3D Pt-Co nanowire assemblies (NWAs) with tunable composition. The composition- and structure-dependent electrocatalytic performance is thoroughly investigated. Because of the bimetallic synergetic effect and unique structural advantage, the as-prepared 3D Pt3Co NWA outperforms commercial Pt/carbon and Pt black catalysts and even 3D Pt NWA. The electrochemical results demonstrate that the 3D Pt3Co NWA is indeed a promising electrocatalyst with enhanced catalytic activity and improved durability for practical electrocatalytic applications.

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Section: Methodssupporting

confidence: 51%

One‐Pot Synthesis of Pt–Co Alloy Nanowire Assemblies with Tunable Composition and Enhanced Electrocatalytic Properties

et al. 2015

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“…Their central portion is darker than their surface, therefore suggesting a core−shell or a hollow nanostructure. X-EDS global and line-scan analyses as well as elemental maps reveal that (i) hollow-type PtNi/C nanoparticles largely predominate, (ii) Ni and Pt atoms are homogeneously distributed within the metal shell but, as a result of acid leaching, 54 the surface and near-surface of the catalysts are enriched in Pt, and (iii) whatever the Pt:Ni ratio in the metal salt precursor solution, the Ni content estimated by X-EDS over eight different zones is close to 10 at % ( Table 1). The slightly larger Ni content found by atomic absorption spectrometry (AAS) confirms our former results that the electrocatalyst contains a small fraction of solid Ni-rich core@ Pt-rich shell nanoparticles.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Tuning the Performance and the Stability of Porous Hollow PtNi/C Nanostructures for the Oxygen Reduction Reaction

et al. 2015

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Due to their increased surface area to volume ratio and molecular accessibility, microporous and mesoporous materials are a promising strategy to electrocatalyze the cathodic oxygen reduction reaction (ORR), the key reaction in proton-exchange membrane fuel cells (PEMFC). Here, we synthesized and provided atomically resolved pictures of porous hollow PtNi/C nanocatalysts, investigated the elemental distribution of Ni and Pt atoms, measured the Pt lattice contraction, and correlated these observations to their ORR activity. The best porous hollow PtNi/C nanocatalyst achieved 6 and 9-fold enhancement in mass and specific activity for the ORR, respectively over standard solid Pt/C nanocrystallites of the same size. The catalytic enhancement was 4 and 3-fold in mass and specific activity, respectively, over solid PtNi/C nanocrystallites with similar chemical composition, Pt lattice contraction, and crystallite size. Furthermore, 100% of the initial mass activity at E = 0.90 V vs RHE (0.56 A mg −1 Pt) of the best electrocatalyst was retained after an accelerated stress test composed of 30 000 potential cycles between 0.60 and 1.00 V vs RHE (0.1 M HClO 4 T = 298 K), therefore meeting the American Department of Energy targets for 2017−2020 both in terms of mass activity and durability (0.44 A mg −1 Pt, mass activity losses < 40%). The better catalytic activity for the ORR of hollow PtNi/C nanocatalysts is ascribed to (i) their opened porosity, (ii) their preferential crystallographic orientation ("ensemble effect"), and (iii) the weakened oxygen binding energy induced by the contracted Pt lattice parameter ("strain effect").

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“…[15][16][17][18] In particular, Pt is a fascinating catalyst because it effectively promotes the process of ORR. [19][20][21] Recently, the oxidation behavior of Pt 3 Zr (0001) surface was studied by the experiment and rst-principles calculations. 22 They found that the weak localized hybridization between Pt and Zr is benecial to oxidation of Zr metal.…”

Section: -14mentioning

confidence: 99%

First-principles study of a new structure and oxidation mechanism of Pt₃Zr

et al. 2017

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Zirconia (ZrO 2 )-metal interfaces are interesting for solid oxide fuel cells. Although the oxidation of Pt 3 Zr provides a new route for the formation of ZrO 2 -Pt interfaces, the crystal structure of Pt 3 Zr remains controversial and the oxidation mechanism of Pt 3 Zr is unclear. To solve these problems, we use firstprinciples calculations to explore the crystal structure of Pt 3 Zr. We demonstrate a stable structure of Pt 3 Zr based on phonon dispersion. Importantly, two new Pt 3 Zr structures, Ti 3 Pt-type (Pm 3m) and Fe 3 Al-type (Fm 3m), are predicted. To study the oxidation mechanism, two possible doped models are considered. The calculated results show that the O atom prefers to occupy the tetrahedral interstitial site (TI) in comparison to the octahedral interstitial site (OI). We find that the oxidizing capacity of the Fe 3 Al-type cubic structure is stronger than that of other structures. In particular, we predict that Pt 3 Zr exhibits better oxidation capacity in comparison to other metals because of the strong localized hybridization between Zr and O.

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Reversibility of Pt-Skin and Pt-Skeleton Nanostructures in Acidic Media

Cited by 49 publications

References 46 publications

One‐Pot Synthesis of Pt–Co Alloy Nanowire Assemblies with Tunable Composition and Enhanced Electrocatalytic Properties

One‐Pot Synthesis of Pt–Co Alloy Nanowire Assemblies with Tunable Composition and Enhanced Electrocatalytic Properties

Tuning the Performance and the Stability of Porous Hollow PtNi/C Nanostructures for the Oxygen Reduction Reaction

First-principles study of a new structure and oxidation mechanism of Pt₃Zr

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Reversibility of Pt-Skin and Pt-Skeleton Nanostructures in Acidic Media

Cited by 49 publications

References 46 publications

One‐Pot Synthesis of Pt–Co Alloy Nanowire Assemblies with Tunable Composition and Enhanced Electrocatalytic Properties

One‐Pot Synthesis of Pt–Co Alloy Nanowire Assemblies with Tunable Composition and Enhanced Electrocatalytic Properties

Tuning the Performance and the Stability of Porous Hollow PtNi/C Nanostructures for the Oxygen Reduction Reaction

First-principles study of a new structure and oxidation mechanism of Pt3Zr

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First-principles study of a new structure and oxidation mechanism of Pt₃Zr