Shape-Controlled Synthesis of Colloidal Platinum Nanoparticles

Ahmadi, Temer S.; Wang, Zhong Lin; Green, Travis C.; Henglein, A.; El‐Sayed, Mostafa A.

doi:10.1126/science.272.5270.1924

Cited by 2,331 publications

(1,620 citation statements)

References 14 publications

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“…[7][8][9][10] Sub-10 nm nanocrystals demonstrate different physical and chemical properties from large nanocrystals. [11][12][13][14][15][16][17][18] Previous research unambiguously showed that the structure dependency of activity and selectivity are more significant for nanocrystals smaller than 10 nm. [3][4][5] Also, smaller nanocrystals have higher dispersion than larger ones and this fact permits more efficient use of precious metals.…”

Section: Introductionmentioning

confidence: 99%

Sub-10 nm Platinum Nanocrystals with Size and Shape Control: Catalytic Study for Ethylene and Pyrrole Hydrogenation

et al. 2009

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Platinum nanocubes and nanopolyhedra with tunable size from 5 nm to 9 nm were synthesized by controlling the reducing rate of metal precursor ions in a one-pot polyol synthesis. A two-stage process is proposed for the simultaneous control of size and shape.In the first stage, the oxidation state of the metal ion precursors determined the nucleation rate and consequently the number of nuclei. The reaction temperature controlled the shape in the second stage by regulation of the growth kinetics. These well-defined nanocrystals were loaded into MCF-17 mesoporous silica for examination of catalytic properties. Pt loadings and dispersions of the supported catalysts were determined by elemental analysis (ICP-MS) and H 2 chemisorption isotherms, respectively. Ethylene hydrogenation rates over the Pt nanocrystals were independent of both size and shape and comparable to Pt single crystals. For pyrrole hydrogenation, the nanocubes enhanced ring opening ability and thus showed a higher selectivity to n-butylamine compared to nanopolyhedra.

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Section: Introductionmentioning

confidence: 99%

Sub-10 nm Platinum Nanocrystals with Size and Shape Control: Catalytic Study for Ethylene and Pyrrole Hydrogenation

et al. 2009

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“…[10][11][12] In each such approach, the effects of shape (zero-, one-, two-or three-dimensional nanostructures), morphology (exposed facets), and catalyst composition on electrocatalytic activity and stability should be considered. [13][14][15][16] In synthesis processes, optimizing catalyst shape, morphology and composition with respect to catalytic activity and stability is critical to achieve successful electrocatalysts.…”

Section: Introductionmentioning

confidence: 99%

Nanostructured Pt-alloy electrocatalysts for PEM fuel cell oxygen reduction reaction

et al. 2010

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In this critical review, we present the current technological advances in proton exchange membrane (PEM) fuel cell catalysis, with a focus on strategies for developing nanostructured Pt-alloys as electrocatalysts for the oxygen reduction reaction (ORR). The achievements are reviewed and the major challenges, including high cost, insufficient activity and low stability, are addressed and discussed. The nanostructured Pt-alloy catalysts can be grouped into different clusters: (i) Pt-alloy nanoparticles, (ii) Pt-alloy nanotextures such as Pt-skins/monolayers on top of base metals, and (iii) branched or anisotropic elongated Pt or Pt-alloy nanostructures. Although some Pt-alloy catalysts with advanced nanostructures have shown remarkable activity levels, the dissolution of metals, including Pt and alloyed base metals, in a fuel cell operating environment could cause catalyst degradation, and still remains an issue. Another concern may be low retention of the nanostructure of the active catalyst during fuel cell operation. To facilitate further efforts in new catalyst development, several research directions are also proposed in this paper (130 references).

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“…In terms of the effects of morphology on electrocatalytic activity, numerous strategies have been developed over the past decades to obtain nanocrystals with preferential shape [8][9][10][11][12][13] , since the shape of a nanoparticle can be directly related to its surface structure 4,14,15 . In the vast majority of cases, it has been necessary to use stabilizing agents to mitigate aggregation and achieve the desired form.…”

Section: Introductionmentioning

confidence: 99%

Identical Location Transmission Electron Microscopy Imaging of Site-Selective Pt Nanocatalysts: Electrochemical Activation and Surface Disordering

Arán‐Ais

Yu²,

Hovden³

et al. 2015

J. Am. Chem. Soc.

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Abstract:We have employed Identical Location Transmission Electron Microscopy (IL-TEM) to study changes in the shape and morphology of faceted Pt nanoparticles as a result of the electrochemical cycling; a procedure typically employed for activating platinum surfaces. We find that the shape and morphology of the as-prepared hexagonal nanoparticles are rapidly degraded as a result of potential cycling up to +1.3 V. As few as 25 potential cycles are sufficient to cause significant degradation, and after about 500-1,000 cycles the particles are dramatically degraded. We also see clear evidence of particle migration during potential cycling. These finding suggest that great care must be exercised in the use and study of shaped Pt nanoparticles (and related systems) as electrocatlysts, especially for the oxygen reduction reaction (ORR) where high positive potentials are typically employed.

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Shape-Controlled Synthesis of Colloidal Platinum Nanoparticles

Cited by 2,331 publications

References 14 publications

Sub-10 nm Platinum Nanocrystals with Size and Shape Control: Catalytic Study for Ethylene and Pyrrole Hydrogenation

Sub-10 nm Platinum Nanocrystals with Size and Shape Control: Catalytic Study for Ethylene and Pyrrole Hydrogenation

Nanostructured Pt-alloy electrocatalysts for PEM fuel cell oxygen reduction reaction

Identical Location Transmission Electron Microscopy Imaging of Site-Selective Pt Nanocatalysts: Electrochemical Activation and Surface Disordering

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