Title: Achieving Highly Durable Random Alloy Nanocatalysts through Intermetallic Cores

Abstract

Pt catalysts are widely studied for the oxygen reduction reaction, but their cost and susceptibility to poisoning limit their use. A strategy to address both problems is to incorporate a second transition metal to form a bimetallic alloy; however, the durability of such catalysts can be hampered by leaching of non-noble metal components. Here, we show that random alloyed surfaces can be stabilized to achieve high durability by depositing the alloyed phase on top of intermetallic seeds using a model system with PdCu cores and PtCu shells. Specifically, random alloyed PtCu shells were deposited on PdCu seeds that were either the atomically random face-centered cubic phase (FCC A1, Fm$$\bar{3}$$m) or the atomically ordered CsCl-like phase (B2, Pm$$\bar{3}$$m). Precise control over crystallite size, particle shape, and composition allowed for comparison of these two core@shell PdCu@PtCu catalysts and the effects of the core phase on electrocatalytic durability. Indeed, the nanocatalyst with the intermetallic core saw only an 18% decrease in activity after stability testing (and minimal Cu leaching), whereas the nanocatalyst with the random alloy core saw a 58% decrease (and greater Cu leaching). The origin of this enhanced durability was probed by classical molecular dynamics simulations of model catalysts, with good agreement between model and experiment. Although many random alloy and intermetallic nanocatalysts have been evaluated, this study directly compares random alloy and intermetallic cores for electrocatalysis with the enhanced durability achieved with the intermetallic cores likely general to other core@shell nanocatalysts.

Authors:

Gamler, Jocelyn T. L. ^[1]; Leonardi, Alberto ^[2]; Ashberry, Hannah M. ^[1]; Daanen, Nicholas N. ^[1]; Losovyj, Yaroslav ^[1]; Unocic, Raymond R.  ^[3];

• Search DOE PAGES for author "Unocic, Raymond R."
• Search DOE PAGES for ORCID "0000-0002-1777-8228"

Engel, Michael  ^[2];

• Search DOE PAGES for author "Engel, Michael"
• Search DOE PAGES for ORCID "0000-0002-7031-3825"

Skrabalak, Sara E.  ^[1]

• Search DOE PAGES for author "Skrabalak, Sara E."
• Search DOE PAGES for ORCID "0000-0002-1873-100X"

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+ Show Author Affiliations

1. Indiana Univ., Bloomington, Indiana (United States). Dept. of Chemistry
2. Friedrich-Alexander Univ. Erlangen-Nürnberg, Erlangen (Germany). Inst. for Multiscale Simulation
3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences

Publication Date:

Mon Apr 08 00:00:00 EDT 2019

Research Org.:

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1561586

Grant/Contract Number:  

AC05-00OR22725

Resource Type:

Accepted Manuscript

Journal Name:

ACS Nano

Additional Journal Information:

Journal Volume: 13; Journal Issue: 4; Journal ID: ISSN 1936-0851

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; electrocatalysts; multimetallic; platinum alloys; nanoparticles; nanocatalysts