skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Revealing the atomic ordering of binary intermetallics using in situ heating techniques at multilength scales

Abstract

Ordered intermetallic nanoparticles are promising electrocatalysts with enhanced activity and durability for the oxygen-reduction reaction (ORR) in proton-exchange membrane fuel cells (PEMFCs). The ordered phase is generally identified based on the existence of superlattice ordering peaks in powder X-ray diffraction (PXRD). However, after employing a widely used postsynthesis annealing treatment, we have found that claims of “ordered” catalysts were possibly/likely mixed phases of ordered intermetallics and disordered solid solutions. Here, we employed in situ heating, synchrotron-based, X-ray diffraction to quantitatively investigate the impact of a variety of annealing conditions on the degree of ordering of large ensembles of Pt 3 Co nanoparticles. Monte Carlo simulations suggest that Pt 3 Co nanoparticles have a lower order–disorder phase transition (ODPT) temperature relative to the bulk counterpart. Furthermore, we employed microscopic-level in situ heating electron microscopy to directly visualize the morphological changes and the formation of both fully and partially ordered nanoparticles at the atomic scale. In general, a higher degree of ordering leads to more active and durable electrocatalysts. The annealed Pt 3 Co/C with an optimal degree of ordering exhibited significantly enhanced durability, relative to the disordered counterpart, in practical membrane electrode assembly (MEA) measurements. The results highlight the importance ofmore » understanding the annealing process to maximize the degree of ordering in intermetallics to optimize electrocatalytic activity.« less

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1491622
Grant/Contract Number:  
EE0007271
Resource Type:
Journal Article: Published Article
Journal Name:
Proceedings of the National Academy of Sciences of the United States of America
Additional Journal Information:
Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Volume: 116 Journal Issue: 6; Journal ID: ISSN 0027-8424
Publisher:
Proceedings of the National Academy of Sciences
Country of Publication:
United States
Language:
English

Citation Formats

Xiong, Yin, Yang, Yao, Joress, Howie, Padgett, Elliot, Gupta, Unmukt, Yarlagadda, Venkata, Agyeman-Budu, David N., Huang, Xin, Moylan, Thomas E., Zeng, Rui, Kongkanand, Anusorn, Escobedo, Fernando A., Brock, Joel D., DiSalvo, Francis J., Muller, David A., and Abruña, Héctor D.. Revealing the atomic ordering of binary intermetallics using in situ heating techniques at multilength scales. United States: N. p., 2019. Web. doi:10.1073/pnas.1815643116.
Xiong, Yin, Yang, Yao, Joress, Howie, Padgett, Elliot, Gupta, Unmukt, Yarlagadda, Venkata, Agyeman-Budu, David N., Huang, Xin, Moylan, Thomas E., Zeng, Rui, Kongkanand, Anusorn, Escobedo, Fernando A., Brock, Joel D., DiSalvo, Francis J., Muller, David A., & Abruña, Héctor D.. Revealing the atomic ordering of binary intermetallics using in situ heating techniques at multilength scales. United States. doi:10.1073/pnas.1815643116.
Xiong, Yin, Yang, Yao, Joress, Howie, Padgett, Elliot, Gupta, Unmukt, Yarlagadda, Venkata, Agyeman-Budu, David N., Huang, Xin, Moylan, Thomas E., Zeng, Rui, Kongkanand, Anusorn, Escobedo, Fernando A., Brock, Joel D., DiSalvo, Francis J., Muller, David A., and Abruña, Héctor D.. Tue . "Revealing the atomic ordering of binary intermetallics using in situ heating techniques at multilength scales". United States. doi:10.1073/pnas.1815643116.
@article{osti_1491622,
title = {Revealing the atomic ordering of binary intermetallics using in situ heating techniques at multilength scales},
author = {Xiong, Yin and Yang, Yao and Joress, Howie and Padgett, Elliot and Gupta, Unmukt and Yarlagadda, Venkata and Agyeman-Budu, David N. and Huang, Xin and Moylan, Thomas E. and Zeng, Rui and Kongkanand, Anusorn and Escobedo, Fernando A. and Brock, Joel D. and DiSalvo, Francis J. and Muller, David A. and Abruña, Héctor D.},
abstractNote = {Ordered intermetallic nanoparticles are promising electrocatalysts with enhanced activity and durability for the oxygen-reduction reaction (ORR) in proton-exchange membrane fuel cells (PEMFCs). The ordered phase is generally identified based on the existence of superlattice ordering peaks in powder X-ray diffraction (PXRD). However, after employing a widely used postsynthesis annealing treatment, we have found that claims of “ordered” catalysts were possibly/likely mixed phases of ordered intermetallics and disordered solid solutions. Here, we employed in situ heating, synchrotron-based, X-ray diffraction to quantitatively investigate the impact of a variety of annealing conditions on the degree of ordering of large ensembles of Pt 3 Co nanoparticles. Monte Carlo simulations suggest that Pt 3 Co nanoparticles have a lower order–disorder phase transition (ODPT) temperature relative to the bulk counterpart. Furthermore, we employed microscopic-level in situ heating electron microscopy to directly visualize the morphological changes and the formation of both fully and partially ordered nanoparticles at the atomic scale. In general, a higher degree of ordering leads to more active and durable electrocatalysts. The annealed Pt 3 Co/C with an optimal degree of ordering exhibited significantly enhanced durability, relative to the disordered counterpart, in practical membrane electrode assembly (MEA) measurements. The results highlight the importance of understanding the annealing process to maximize the degree of ordering in intermetallics to optimize electrocatalytic activity.},
doi = {10.1073/pnas.1815643116},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
number = 6,
volume = 116,
place = {United States},
year = {Tue Feb 05 00:00:00 EST 2019},
month = {Tue Feb 05 00:00:00 EST 2019}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on August 5, 2019
Publisher's Version of Record

Save / Share:

Works referenced in this record:

Structurally ordered intermetallic platinum�cobalt core�shell nanoparticles with enhanced activity and stability as oxygen reduction electrocatalysts
journal, October 2012

  • Wang, Deli; Xin, Huolin L.; Hovden, Robert
  • Nature Materials, Vol. 12, Issue 1, p. 81-87
  • DOI: 10.1038/nmat3458

Tuning Oxygen Reduction Reaction Activity via Controllable Dealloying A Model Study of Ordered Cu3Pt/C Intermetallic Nanocatalysts
journal, September 2012

  • Wang, Deli; Yu, Yingchao; Xin, Huolin L.
  • Nano Letters, Vol. 12, Issue 10, p. 5230-5238
  • DOI: 10.1021/nl302404g

Gold-promoted structurally ordered intermetallic palladium cobalt nanoparticles for the oxygen reduction reaction
journal, November 2014

  • Kuttiyiel, Kurian A.; Sasaki, Kotaro; Su, Dong
  • Nature Communications, Vol. 5, Article No. 5185
  • DOI: 10.1038/ncomms6185

Trends in electrocatalysis on extended and nanoscale Pt-bimetallic alloy surfaces
journal, February 2007

  • Stamenkovic, Vojislav R.; Mun, Bongjin Simon; Arenz, Matthias
  • Nature Materials, Vol. 6, Issue 3, p. 241-247
  • DOI: 10.1038/nmat1840