Core-level binding energy shifts in Pt–Ru nanoparticles: A puzzle resolved

Lewera, Adam; Zhou, Wei; Hunger, R.; Jaegermann, Wolfram; Wiȩckowski, Andrzej; Yockel, Scott; Bagus, Paul S.

doi:10.1016/j.cplett.2007.08.068

Cited by 35 publications

(39 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The enhanced E b of Pt 4f for Pt-Ru/NCNT comes from the shift of d-band center towards higher E b , which is caused by the lattice strain and charge transfer due to the Ru alloying [17][18][19]. Similar E b changes for Pt and Ru were observed in Pt-Ru bulk alloys [17]. These results indicate that both the chemical composition and the electron state in the Pt-Ru/NCNT catalysts have been controllably regulated.…”

Section: Resultssupporting

confidence: 70%

“…3a), while the E b for Ru 3p 3/2 does not show observable shift with respect to that for Ru/NCNT. The enhanced E b of Pt 4f for Pt-Ru/NCNT comes from the shift of d-band center towards higher E b , which is caused by the lattice strain and charge transfer due to the Ru alloying [17][18][19]. Similar E b changes for Pt and Ru were observed in Pt-Ru bulk alloys [17].…”

Section: Resultssupporting

confidence: 67%

See 1 more Smart Citation

Direct immobilization of Pt–Ru alloy nanoparticles on nitrogen-doped carbon nanotubes with superior electrocatalytic performance

Jiang

Zhu

et al. 2010

Journal of Power Sources

View full text Add to dashboard Cite

Section: Resultssupporting

confidence: 70%

Section: Resultssupporting

confidence: 67%

Direct immobilization of Pt–Ru alloy nanoparticles on nitrogen-doped carbon nanotubes with superior electrocatalytic performance

Jiang

Zhu

et al. 2010

Journal of Power Sources

View full text Add to dashboard Cite

“…27,28 The observed changes in binding energy of core−shell catalysts could be attributed to the electronic coupling between the Pt shell and Pd substrate. 29 Meanwhile, a compressive lattice strain induced by placing the Pt shell with a lager lattice parameter (3.9232 Å) on a Pd substrate with a smaller lattice parameter (3.8898 Å) would be another factor causing the positive shift of Pt 4f signals in our core−shell particles. 30−32 Furthermore, as shown in Figure 4a,b, clearly, the Pd@Pt/C catalyst exhibits higher Pt 0 proportion (66.6%) than that in commercial Pt/C catalyst (54.5%).…”

Section: Resultsmentioning

confidence: 99%

High-Performance, Ultralow Platinum Membrane Electrode Assembly Fabricated by In Situ Deposition of a Pt Shell Layer on Carbon-Supported Pd Nanoparticles in the Catalyst Layer Using a Facile Pulse Electrodeposition Approach

et al. 2015

View full text Add to dashboard Cite

An ultralow platinum loading membrane electrode assembly (MEA) is prepared by a facile synthesis process in which pulse electrodeposition is used to achieve a catalyst layer by the in situ decoration of carbon-supported Pd nanoparticles with a thin layer of Pt atoms. The novel MEA exhibits excellent performance in a H 2 /air single fuel cell, with Pt loading of as little as 0.015 mg cm −2 at the anode and 0.04 mg cm −2 at the cathode, outperforming the commercial Pt/C MEA (Johnson Matthey, 40 wt % Pt). The shift in binding energy of the XPS peak of Pd and Pt in the Pd@Pt/C MEA confirms the presence of the Pt shell and the interaction between the shell and the Pd core. We suggest that the high performance of this Pd@Pt/C MEA may be due to several factors: high Pt dispersion arising from the core−shell structure, high Pt utilization because there is no Nafion binder covering the Pt, the quantum effect caused by the high distribution of Pt, and the interaction between the Pt shell and the Pd in the core.

show abstract

“…46 A slight deviation is expected, because there is a minor shift of Ru signals ͑less than 0.1 eV͒ in the PtRu from that of metallic Ru. 47 Nevertheless, our broad signals seem to suggest that Ru existed in multiple oxidative states. Furthermore, the XPS signal intensity decreased considerably with longer T off , indi- cating that the amount of Ru, regardless of its oxidative states, decreases when the duty is reduced.…”

Section: B738mentioning

confidence: 93%

Displacement Reaction in Pulse Current Deposition of PtRu for Methanol Electro-Oxidation

Hsieh¹,

Wu²,

Lu³

et al. 2009

J. Electrochem. Soc.

View full text Add to dashboard Cite

Galvanostatic depositions in rectangular pulses and nitrosol precursors were employed to prepare PtRu nanoparticles on carbon clothes in various sizes and compositions. Variables including current on-time ͑T on ͒, current off-time ͑T off ͒, and current density were explored to identify the optimized catalytic performances for methanol electro-oxidation. Electrochemical characterizations including cyclic voltammetry and hydrogen desorption were carried out. Images from a transmission electron microscope on the PtRu nanoparticles revealed a moderate size distribution. Signals from X-ray patterns indicated a slight shift of diffraction peaks, suggesting that the Ru was alloyed successfully in the Pt lattice. In addition, the amount of alloyed Ru was found to decrease with reduced duty cycles. Composition determinations from inductively coupled plasma mass spectrometry and analysis on the oxidation states from X-ray photoelectron spectroscopy suggested a displacement reaction in which the Ru was alternately deposited and dissolved during T on and T off , while the Pt was deposited continuously. As a result, we observed substantial enrichment of Pt in the PtRu nanoparticles when the duty cycle was shortened.Development of clean and affordable energy has attracted considerable attention due to rising concerns over oil price and harmful CO 2 emission. Among the possible systems under study, the direct methanol fuel cell ͑DMFC͒ is recognized as a promising power source for applications in portable electronics and transportations. 1,2 Because electro-oxidation of methanol is intrinsically slow, many materials have been investigated as electrocatalysts at the anode. They include alloys in binary, tertiary, and quaternary compositions such as PtRu, PtCo, PtRuCo, and PtRuNiZr. 3-7 So far, the PtRu has appeared as the leading candidate with superb electrocatalytic performance. It is because by alloying with Ru, the undesirable Pt poisoning by CO could be largely reduced. Mechanisms including bifunctional effect and ligand model are proposed to explain the contributory role of Ru while alloying with Pt. 8,9 Moreover, the catalytic behaviors of PtRu depend greatly on its surface composition. For example, Richarz et al. prepared the Pt x Ru 1−x in various compositions and determined the Pt 0.5 Ru 0.5 to possess the highest activity for methanol electro-oxidation. 10 In practice, the PtRu is impregnated on appropriate carbon supports for an extended reaction interface. Conventional synthetic approaches for the PtRu-catalyzed electrodes entail techniques in chemical reduction and hydrogen annealing. 11,12 These methods add substantial difficulties in controlling the locations and compositions of the resulting PtRu nanoparticles. In contrast, approaches involving electrochemical reductions are rather straightforward. Because the growths of PtRu nanoparticles are occurring selectively at the interface between electrode and electrolyte, the electrodeposition routes are recognized to produce electrodes with exceptional efficiencies in...

show abstract

Core-level binding energy shifts in Pt–Ru nanoparticles: A puzzle resolved

Cited by 35 publications

References 26 publications

Direct immobilization of Pt–Ru alloy nanoparticles on nitrogen-doped carbon nanotubes with superior electrocatalytic performance

Direct immobilization of Pt–Ru alloy nanoparticles on nitrogen-doped carbon nanotubes with superior electrocatalytic performance

High-Performance, Ultralow Platinum Membrane Electrode Assembly Fabricated by In Situ Deposition of a Pt Shell Layer on Carbon-Supported Pd Nanoparticles in the Catalyst Layer Using a Facile Pulse Electrodeposition Approach

Displacement Reaction in Pulse Current Deposition of PtRu for Methanol Electro-Oxidation

Contact Info

Product

Resources

About