Article

Platinum-monolayer shell on AuNi(0.5)Fe nanoparticle core electrocatalyst with high activity and stability for the oxygen reduction reaction.

Brookhaven National Laboratory, Upton, New York 11973, USA.
Journal of the American Chemical Society (impact factor: 9.91). 10/2010; 132(41):14364-6. DOI:10.1021/ja1063873 pp.14364-6
Source: PubMed

ABSTRACT We describe a simple method for preparing multimetallic nanoparticles by in situ decomposition of the corresponding Prussian blue analogue, which is adsorbed on carbon black. The example involves the AuNi(0.5)Fe core of the Pt(ML)/Au(1)Ni(0.5)Fe core-shell electrocatalyst for the oxygen reduction reaction. The core contains 3-5 surface atomic layers of Au, which play an essential role in determining the activity and stability of the catalyst. The Pt(ML)/AuNi(0.5)Fe electrocatalyst exhibited Pt mass and specific activities of 1.38 A/mg(Pt) and 1.12 × 10(-3) A/cm(2)(Pt), respectively, both of which are several times higher than those of commercial Pt/C catalysts. Its all-noble-metal mass activity (0.18 A/mg(Pt,Au)) is higher than or comparable to those of commercial samples. Stability tests showed an insignificant loss in activity after 15,000 triangular-potential cycles. We ascribe the high activity and stability of the Pt(ML)/AuNi(0.5)Fe electrocatalyst to its hierarchical structural properties, the Pt-core interaction, and the high electrochemical stability of the gold shell that precludes exposure to the electrolyte of the relatively active inner-core materials.

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Keywords

15,000 triangular-potential cycles
 
carbon black
 
catalyst
 
commercial Pt/C catalysts
 
corresponding Prussian blue analogue
 
electrochemical stability
 
essential role
 
hierarchical structural properties
 
oxygen reduction reaction
 
precludes exposure
 
Pt(ML)/Au(1)Ni(0.5)Fe core-shell electrocatalyst
 
Pt(ML)/AuNi(0.5)Fe electrocatalyst
 
Pt(ML)/AuNi(0.5)Fe electrocatalyst exhibited Pt mass
 
Pt-core interaction
 
situ decomposition
 
specific activities
 
Stability tests
 
times higher
 

Kuanping Gong