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Surface segregation effects in electrocatalysis: Kinetics of oxygen reduction reaction on polycrystalline Pt3Ni alloy surfaces
TLDR
Stamenkovic et al. as discussed by the authors studied the effects of surface segregation on the oxygen reduction reaction (ORR) on polycrystalline Pt Ni alloy in acid electrolyte using ultra high vacuum (UHV) surface sensitive probes and the rotating ring disk electrode (RRDE).Abstract:
Submitted to the Journal of Electroanalytical Chemistry, November 6, 2002 Surface Segregation Effects in Electrocatalysis: Kinetics of Oxygen Reduction Reaction on Polycrystalline Pt Ni Alloy Surfaces** V. Stamenkovic*, T.J. Schmidt - , P.N. Ross and N . M . Markovic Materials Sciences Division, Lawrence Berkeley National Laboratory University of California at Berkeley, CA 94720, USA Abstract Effects of surface segregation on the oxygen reduction reaction (ORR) have been studied on a polycrystalline Pt Ni alloy in acid electrolyte using ultra high vacuum (UHV) surface sensitive probes and the rotating ring disk electrode (RRDE) method. Preparation, modification and Depending on the characterization of alloy surfaces were done in ultra high vacuum (UHV). preparation method, two different surface compositions of the Pt Ni alloy are produced: a sputtered surface with 75 % Pt and an annealed surface (950 K ) with 100 % Pt. The latter surface is designated as the Pt-skin structure, and is a consequence of surface segregation, i.e., replacement of N i with Pt atoms in the first few atomic layers. Definitive surface compositions were established by low energy ion scattering spectroscopy (LEISS). The cyclic voltammetry of the Pt-skin surface as well as the pseudcapacitance in the hydrogen adsorption/desorption potential region is similar to a polycrystalline Pt electrode. Activities of ORR on Pt Ni alloy surfaces were compared to polycrystalline Pt in 0.1M H C l O electrolyte for the observed temperature range of 293 Pt Ni (75% Pt) > Pt with the maximum catalytic enhancement obtained for the Pt-skin being 4 timesread more
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Trends in electrocatalysis on extended and nanoscale Pt-bimetallic alloy surfaces
Vojislav R. Stamenkovic,Vojislav R. Stamenkovic,Bongjin Simon Mun,Bongjin Simon Mun,Matthias Arenz,Karl Johann Jakob Mayrhofer,Chris Lucas,Guofeng Wang,Philip N. Ross,Nenad M. Markovic +9 more
TL;DR: The electrocatalytic trends established for extended surfaces are used to explain the activity pattern of Pt(3)M nanocatalysts as well as to provide a fundamental basis for the catalytic enhancement of cathode catalysts.
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Carbon-Supported Pt-Based Alloy Electrocatalysts for the Oxygen Reduction Reaction in Polymer Electrolyte Membrane Fuel Cells: Particle Size, Shape, and Composition Manipulation and Their Impact to Activity
TL;DR: Reduction Reaction in Polymer Electrolyte Membrane Fuel Cells: Particle Size, Shape, and Composition Manipulation and Their Impact to Activity
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Low-platinum and platinum-free catalysts for the oxygen reduction reaction at fuel cell cathodes
TL;DR: In this article, a review of ORR catalysts with regard to their classification, mechanism, activity and performances is presented, from conventional Pt-based catalysts to non-noble metal or bio-inspired catalysts.
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Electrocatalysis for Polymer Electrolyte Fuel Cells: Recent Achievements and Future Challenges
TL;DR: In this article, a focused overview summarizing the most outstanding contributions in the last 10 years in terms of activity and durability of the catalyst materials for ethanol oxidation and oxygen reduction reaction, respectively.
References
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Journal ArticleDOI
Surface science studies of model fuel cell electrocatalysts
Nenad M. Markovic,Philip N. Ross +1 more
TL;DR: In this paper, the authors discuss progress in the understanding of electrocatalytic reactions through the study of model systems with surface spectroscopies and discuss the limitations of using pure metal single crystals and well-characterized bulk alloys as models for real catalysts.
Journal ArticleDOI
Oxygen Reduction on Carbon-Supported Pt−Ni and Pt−Co Alloy Catalysts
U. A. Paulus,and A. Wokaun,Guenther G. Scherer,Thomas J. Schmidt,Vojislav R. Stamenkovic,Velimir Radmilovic,and N. M. Markovic,Philip N. Ross +7 more
TL;DR: In this article, a comparative study of the oxygen reduction reaction on two carbon-supported Pt-based alloy catalysts in aqueous acidic electrolyte at low temperature is presented.
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Methanol electrooxidation on well-characterized platinum-ruthenium bulk alloys
TL;DR: In this paper, the catalytic activity of single-phase polycrystalline Pt-Ru bulk alloys toward the electrooxidation of methanol in sulfuric acid electrolyte at room temperature was measured for the first time on well-characterized alloy surfaces, in terms of surface composition and true surface area.
Journal ArticleDOI
Temperature-dependent oxygen electrochemistry on platinum low-index single crystal surfaces in acid solutions
TL;DR: Using the rotating ring disk technique (RRDPt(hkl)E), the ORR was studied in sulfuric acid solution over the temperature range 298 −333 K at the same temperature, the exc...
Journal ArticleDOI
Surface Composition Effects in Electrocatalysis: Kinetics of Oxygen Reduction on Well-Defined Pt3Ni and Pt3Co Alloy Surfaces
TL;DR: In this article, the surface composition of polycrystalline bulk alloys of Pt3Ni and Pt3Co was determined via low-energy ion-scattering (LEIS) spectroscopy.