Engineering Structurally Ordered High-Entropy Intermetallic Nanoparticles with High-Activity Facets for Oxygen Reduction in Practical Fuel Cells

Guang Feng; Fanghua Ning; Yue Pan; Tao Chen; Jin Song; Yucheng Wang; Ruqiang Zou; Dong Su; Dingguo Xia

doi:10.1021/jacs.3c00868

Engineering Structurally Ordered High-Entropy Intermetallic Nanoparticles with High-Activity Facets for Oxygen Reduction in Practical Fuel Cells

J Am Chem Soc. 2023 May 24;145(20):11140-11150. doi: 10.1021/jacs.3c00868. Epub 2023 May 9.

Authors

Guang Feng¹, Fanghua Ning¹, Yue Pan², Tao Chen¹, Jin Song¹, Yucheng Wang³, Ruqiang Zou¹, Dong Su², Dingguo Xia^{1

4}

Affiliations

¹ Beijing Key Laboratory of Theory and Technology for Advanced Batteries Materials, School of Materials Science and Engineering, Peking University, Beijing 100871, P. R. China.
² Beijing National Laboratory for Condensed Matter Physics Institute of Physics, Chinese Academy of Sciences, Beijing 100190, P. R. China.
³ State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative innovation center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China.
⁴ Beijing Innovation Center for Engineering Science and Advanced Technology, Peking University, Beijing 100871, P. R. China.

PMID: 37161344
DOI: 10.1021/jacs.3c00868

Abstract

High-entropy solid-solution alloys have generated significant interest in energy conversion technologies. However, structurally ordered high-entropy intermetallic (HEI) nanoparticles (NPs) have been rarely reported in electrocatalysis applications. Here, we demonstrate structurally ordered PtIrFeCoCu HEI (PIFCC-HEI) NPs with extremely superior performance for both oxygen reduction reaction (ORR) and H₂/O₂ fuel cells. The PIFCC-HEI NPs show an average diameter of 6 nm. Atomic structural characterizations including atomic-resolution energy-dispersive spectroscopy (EDS) mapping technology confirm the ordered intermetallic structure of PIFCC-HEI NPs. As an electrocatalyst for ORR, the PIFCC-HEI/C achieves an ultrahigh mass activity of 7.14 A mg_{noble metals}^-1 at 0.85 V and extraordinary durability over 60 000 potential cycles. Moreover, the fuel cell assembled with PIFCC-HEI/C as the cathode delivers an ultrahigh peak power density of 1.73 W cm^-2 at a back pressure of 1.0 bar and almost no working voltage decay after 80 h operation, certifying the top-level performance among reported fuel cells. Theoretical calculations combined with experimental results reveal that the superior performance of PIFCC-HEI/C for ORR and fuel cells is attributed to its ultrahigh-activity facets. Especially, the (001) facet affords the lowest activation barriers for the rate-limiting step, the optimal downshift of the d-band center, and more efficient regulation of electron structures for ORR. This work not only opens up a new avenue for the fabrication of high-activity facets in the catalysts but also highlights structurally ordered HEI NPs as sufficiently effective catalysts in practical fuel cells and other potential energy-related applications.