Atomically resolved dealloying of structurally ordered Pt nanoalloy as an oxygen reduction reaction electrocatalyst
The positive effect of intermetallic ordering of platinum alloy nanoparticles on oxygen reduction reaction (ORR) activity has been well established. What is still missing is an understanding of selective leaching of the less noble metal from the ordered structure and its correlation to longterm ORR performance. Using a combination of kinetic Monte Carlo simulations and advanced characterization techniques, we provide unprecedented insight into dealloying of intermetallic PtCu3 nanoparticles a well-known binary alloy. Comparison of ordered and disordered samples with identical initial compositions and particle size distributions reveals an unexpected correlation: whereas the copper dealloying rates in the ordered and disordered counterparts are almost the same, in the ordered structure Pt atoms are surrounded by 15−30% more Cu atoms throughout all the stages of acid leaching. This more convenient Pt−Cu coordination explains the statistically significant increase of 23−37% in ORR activity of the ordered structure at all stages of alloy degradation.
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2016-09-27 11:52:00
1033
materiali, elektrokataliza, nanozlitine, struktura snovi
r6
Andraž
Pavlišič
70
Primož
Jovanovič
70
Vid Simon
Šelih
70
Martin
Šala
70
Marjan
Bele
70
Goran
Dražić
70
Iztok
Arčon
70
Samo B.
Hočevar
70
Anton
Kokalj
70
Nejc
Hodnik
70
Miran
Gaberšček
70
ISSN pri članku
9
2155-5435
OceCobissID
13
518529817
DOI
15
10.1021/acscatal.6b00557
NUK URN
18
URN:SI:UNG:REP:HSTI1NAY
Cu_Pt_catalyst_reprint_support.pdf
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