Ordered alloy formation for Pt3Fe/C, PtFe/C and Pt5.75Fe5.75Cuy/CO2-reduction electro-catalysts

Chen, L.; Bock, Christina; Mercier, Patrick H. J.; MacDougall, B.

doi:10.1016/j.electacta.2012.05.103

Cited by 45 publications

(41 citation statements)

References 33 publications

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“…Catalysts design for the oxygen reduction reaction (ORR) in a proton‐exchange membrane fuel cell (PEMFC), in particular, is an area that has received momentous thrust as an effect. The principal findings of this research effort provide much expansive insight into the fundamental understanding of nanoscale materials . Although platinum (Pt) is known to exhibit exceptional activity towards the sluggish ORR kinetics, it still remains an economically nonviable option for large‐scale implementation of PEMFC, owing to its depleting natural sources and exceedingly high costs .…”

Section: Resultsmentioning

confidence: 99%

“…Pt–Fe system, in particular, has gathered a lot of interest in recent years not only on the account of its enhanced ORR electrocatalysis, but also because of its magnetic properties that are deployable in ultrahigh‐density information storage . The PtFe (L1 0 ) ordered phase exhibits a very high uniaxial magnetocrystalline anisotropy along the c direction of the crystal structure.…”

Section: Resultsmentioning

confidence: 99%

“…Therefore, the chemical synthesis of Pt–Fe alloy nanoparticles in these ordered phases has been extensively studied in the past years. For example, novel alloy structures such as intermetallic Pt–Fe/Pt core shells, Pt–Fe–Cu ternary alloy nanoparticles, monodisperse Ni/FePt core shells, and face‐centered tetragonal (fct) FePt nanoparticles have been explored with reported ORR specific activities of 0.55 mA cm −2 , 0.75 mA cm −2 , 1.95 mA cm −2 , and 3.16 mA cm −2 , respectively. Unfortunately, the wet‐chemical synthesis yields disordered nanoparticles in the face‐centered cubic (fcc) A1 phase.…”

Section: Resultsmentioning

confidence: 99%

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Surface Segregation of Fe in Pt–Fe Alloy Nanoparticles: Its Precedence and Effect on the Ordered‐Phase Evolution during Thermal Annealing

et al. 2015

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Coupling electron microscopy techniques with in situ heating ability allows us to study phase transformations on the single-nanoparticle level. We exploit this setup to study disorder-to-order transformation of Pt–Fe alloy nanoparticles, a material that is of great interest to fuel-cell electrocatalysis and ultrahigh density information storage. In contrast to earlier reports, we show that Fe (instead of Pt) segregates towards the particle surface during annealing and forms a Fe-rich FeOx outer shell over the alloy core. By combining both ex situ and in situ approaches to probe the interplay between ordering and surface-segregation phenomena, we illustrate that the surface segregation of Fe precedes the ordering process and affects the ordered phase evolution dramatically. We show that the ordering initiates preferably at the pre-existent Fe-rich shell than the particle core. While the material-specific findings from this study open interesting perspectives towards a controlled phase evolution of Pt–Fe nanoalloys, the characterization methodologies described are general and should prove useful to probing a wide-range of nanomaterials.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Surface Segregation of Fe in Pt–Fe Alloy Nanoparticles: Its Precedence and Effect on the Ordered‐Phase Evolution during Thermal Annealing

et al. 2015

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“…Many studies have focused on alloy catalysts of Pt-M, such as M = Cu, 16,17 Co, 18 Ni, 19,20 Cr, 21 Fe, 22,23 hoping to enhance Pt catalysis and lower Pt loading. The observed enhancement of electrocatalytic activity is strongly correlated to the compression of the Pt lattice, 24 and the low durability results from the easy dissolution and leaching of base metals in the acid media with oxygen saturated.…”

Section: Introductionmentioning

confidence: 99%

Fine-grained and fully ordered intermetallic PtFe catalysts with largely enhanced catalytic activity and durability

Wang

et al. 2016

Energy Environ. Sci.

179

116

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In the global plan towards a sustainable energy future, proton exchange membrane fuel cell (PEMFC) technology enables high energy density, zero emission and efficient energy conversion and is therefore considered as a promising power source based on renewable energy. So far, this technology has not been commercialized to compete with conventional power sources, due to its low performance and high manufacturing cost. Electrocatalyst is one of the key materials determining the performance and cost of PEMFC as it is required for catalyzing the chemical reactions involved in fuel cell operation. Up to now, platinum is still the most widely used catalyst, and its high price and low stability hinder the final commercialization of PEMFC. This study develops a new catalyst based on Pt and Fe. The new catalyst has a fully ordered intermetallic structure and is entrapped within thin carbon layers. Experimental evidence shows that such a catalyst possesses a catalytic activity and durability much higher than conventional pure Pt catalyst. This finding is useful for reducing the Pt usage, improving the performance, and promoting the application of PEMFC. † Electronic Supplementary Information (ESI) available: Grain size distributions of PtFe/C, N 2 adsorption/desorption isotherms, XRD patterns for PtFe and PtFe 1.8 samples, TEM images of JM Pt/C catalyst, Potential cycling between 0.6 and 1.0 V, ORR polarization curves for different catalysts, CV curves and ECSA results, TEM images and particle sizes after ADT. See Catalytic activity and durability improvements are still the main challenges for fuel cell commercialization. To enhance nanocatalyst performance and durability for oxygen reduction reaction (ORR), we prepare 3.6 nm sized PtFe particles with a fully ordered intermetallic structure and entrap them in a porous carbon (PtFe@C). This nanocatalyst toward ORR exhibits 8-10 times enhancement in specific and mass activities over the commercial catalyst of Pt/C. Such a large enhancement is the highest, when compared with all other kinds of intermetallic catalysts reported in the literature.Accelerated durability testing has induced only a small change to the ordered structure and a minor loss of the activity after thousands of potential cycles under harsh electrochemical conditions. The high activity and durability are attributed to the fine-grained and ordered structure of the nanoparticle and the confining effect provided by the porous carbon. The nanoparticle, PtFe@C, represents a new strategy for performance optimization and cost reduction and promoting practical applications of fuel cells.

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“…The information of the crystal structures was first acquired by high‐resolution TEM (HRTEM). As shown in Figure c, the lattice constant for a single nanodendrite was calculated to be approximately 0.218 nm, showing a cyclical lattice stretching after the formation of the alloy phase . Further structural properties were received through powder X‐ray diffraction (PXRD).…”

Section: Figurementioning

confidence: 99%

High‐Quality Platinum–Iron Nanodendrites with a Multibranched Architecture as Efficient Electrocatalysts for the Ethanol Oxidation Reaction

Song

Wang

et al. 2018

ChemCatChem

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Although great success has been made in the design of well‐defined nanocrystals (NCs) with various morphologies, a facile method to prepare desirable NCs with large active surface areas and unique facets remains an arduous challenge. Herein, we demonstrate a facile method for the successful synthesis of high‐quality PtFe nanodendrites with a multibranched architecture; these nanodendrites have an abundance of exposed surface active sites that are available for ethanol molecules. Detailed study of its electrocatalytic properties revealed that the resultant superbranched PtFe nanocatalysts displayed superior electrocatalytic activity towards ethanol oxidation with unprecedentedly high mass/specific activities of 3692.5 mA mg−1 and 7.02 mA cm−2; these values are 9.3 and 10.0‐fold higher than those of a commercial Pt/C catalyst, signifying that the these nanodendrites may serve as highly efficient catalysts for fuel cells and beyond.

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Ordered alloy formation for Pt3Fe/C, PtFe/C and Pt5.75Fe5.75Cuy/CO2-reduction electro-catalysts

Cited by 45 publications

References 33 publications

Surface Segregation of Fe in Pt–Fe Alloy Nanoparticles: Its Precedence and Effect on the Ordered‐Phase Evolution during Thermal Annealing

Surface Segregation of Fe in Pt–Fe Alloy Nanoparticles: Its Precedence and Effect on the Ordered‐Phase Evolution during Thermal Annealing

Fine-grained and fully ordered intermetallic PtFe catalysts with largely enhanced catalytic activity and durability

High‐Quality Platinum–Iron Nanodendrites with a Multibranched Architecture as Efficient Electrocatalysts for the Ethanol Oxidation Reaction

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