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Published April 26, 2023 | public
Journal Article

Improving Oxygen Reduction Performance of Surface-Layer-Controlled Pt–Ni Nano-Octahedra via Gaseous Etching


This study demonstrates an atomic composition manipulation on Pt–Ni nano-octahedra to enhance their electrocatalytic performance. By selectively extracting Ni atoms from the {111} facets of the Pt–Ni nano-octahedra using gaseous carbon monoxide at an elevated temperature, a Pt-rich shell is formed, resulting in an ∼2 atomic layer Pt-skin. The surface-engineered octahedral nanocatalyst exhibits a significant enhancement in both mass activity (∼1.8-fold) and specific activity (∼2.2-fold) toward the oxygen reduction reaction compared with its unmodified counterpart. After 20,000 potential cycles of durability tests, the surface-etched Pt–Ni nano-octahedral sample shows a mass activity of 1.50 A/mg_(Pt), exceeding the initial mass activity of the unetched counterpart (1.40 A/mg_(Pt)) and outperforming the benchmark Pt/C (0.18 A/mg_(Pt)) by a factor of 8. DFT calculations predict this improvement with the Pt surface layers and support these experimental observations. This surface-engineering protocol provides a promising strategy for developing novel electrocatalysts with improved catalytic features.

Additional Information

© 2023 American Chemical Society. This work was primarily supported by the National Science Foundation (NSF) under grant DMR-1808383. The theoretical work used the Extreme Science and Engineering Discovery Environment (XSEDE) for DFT calculations, which is supported by the NSF under grant ACI-1548562. W.A.G. is thankful for support by the NSF (CBET-2005250, program manager: Bob McCabe), S.K. acknowledges support from the Resnick Sustainability Institute at Caltech; X.C. and G.Z. are thankful for the financial support by the NSF under grant DMR-1905422. L.Z. acknowledges the use of TEM facilities for the structural characterizations, at the Center for Functional Nanomaterials, which is a U.S. Department of Energy Office of Science User Facility, at Brookhaven National Laboratory under Contract No. DE-SC0012704. Partial low-magnification TEM imaging work was supported by S3IP/ADL, the State University of New York at Binghamton. Author Contributions. C.L., S.K., and X.C. contributed equally to this work. The authors declare no competing financial interest.

Additional details

August 22, 2023
October 20, 2023