Title: Synthesis of Ru Icosahedral Nanocages with a Face-Centered-Cubic Structure and Evaluation of Their Catalytic Properties

Abstract

Owing to the presence of {111} facets, twin boundaries, and strain fields on the surface, noble-metal nanocrystals with an icosahedral shape have been reported with stellar performance toward an array of catalytic reactions. Here, we report the successful synthesis of Ru icosahedral nanocages with a face-centered cubic (fcc) structure by conformally coating Pd icosahedral seeds with ultrathin Ru shells, followed by selective removal of the Pd cores via chemical etching. We discovered that the presence of bromide ions was critical to the layer-by-layer deposition of Ru atoms. According to in situ XRD, the fcc structure in the Ru nanocages could be retained up to 300 °C before it was transformed into the conventional hexagonal close-packed (hcp) structure. Additionally, the icosahedral shape of the Ru nanocages could be largely preserved up to 300 °C. The Ru icosahedral nanocages with twin boundaries on the surface exhibited greatly enhanced activities toward both the reduction of 4-nitrophenol and decomposition of hydrazine than their cubic and octahedral counterparts. When benchmarked against the parental Pd@Ru core–shell nanocrystals, all the Ru nanocages displayed superior catalytic activities. First-principles density functional theory calculations also suggest that the fcc-Ru icosahedral nanocages containing residual Pd atoms are more promising than themore » conventional hcp-Ru solid nanoparticles in catalyzing nitrogen reduction for ammonia synthesis. With the subsurface impurities of Pd, the twin boundary regions of the icosahedral nanocages are able to stabilize the N₂ dissociation transition state, reducing the overall reaction barrier and promoting the competition with the N₂ desorption process.« less

Authors:

Zhao, Ming  ^[1];

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• Search DOE PAGES for ORCID "0000-0003-0127-1470"

Xu, Lang ^[2]; Vara, Madeline  ^[1];

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• Search DOE PAGES for ORCID "0000-0001-8968-8734"

Elnabawy, Ahmed O.  ^[2];

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• Search DOE PAGES for ORCID "0000-0002-8911-1916"

Gilroy, Kyle D.  ^[3];

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• Search DOE PAGES for ORCID "0000-0002-3153-8060"

Hood, Zachary D. ^[4]; Zhou, Shan  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-6476-3280"

Figueroa-Cosme, Legna ^[1]; Chi, Miaofang  ^[5];

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• Search DOE PAGES for ORCID "0000-0003-0764-1567"

Mavrikakis, Manos  ^[2];

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Xia, Younan  ^[6]

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• Search DOE PAGES for ORCID "0000-0003-2431-7048"

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+ Show Author Affiliations

1. Georgia Inst. of Technology, Atlanta, GA (United States). School of Chemistry and Biochemistry
2. Univ. of Wisconsin, Madison, WI (United States). Dept. of Chemical and Biological Engineering
3. Georgia Inst. of Technology and Emory Univ., Atlanta, GA (United States). Wallace H. Coulter Dept. of Biomedical Engineering
4. Georgia Inst. of Technology, Atlanta, GA (United States). School of Chemistry and Biochemistry; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS)
5. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS)
6. Georgia Inst. of Technology, Atlanta, GA (United States). School of Chemistry and Biochemistry; Georgia Inst. of Technology and Emory Univ., Atlanta, GA (United States). Wallace H. Coulter Dept. of Biomedical Engineering

Publication Date:

Fri May 25 00:00:00 EDT 2018

Research Org.:

Univ. of Wisconsin, Madison, WI (United States)

Sponsoring Org.:

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

Contributing Org.:

Georgia Institute of Technology’s Institute of Electronics and Nanotechnology (IEN) facilities; Oak Ridge National Laboratory’s Center for Nanophase Materials Sciences; EMSL at PNNL; CNM at ANL; and the UW-Madison Center for High Throughput Computing (CHTC)

OSTI Identifier:

1494814

Grant/Contract Number:  

FG02-05ER15731

Resource Type:

Accepted Manuscript

Journal Name:

ACS Catalysis

Additional Journal Information:

Journal Volume: 8; Journal Issue: 8; Journal ID: ISSN 2155-5435

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Density functional theory; facet-dependent catalysis; fcc structure; nanocages; ruthenium