High-entropy L12-Pt(FeCoNiCuZn)3 intermetallics for ultrastable oxygen reduction reaction

Enhancing the stability of Pt-based electrocatalysts for the sluggish cathodic oxygen reduction reaction (ORR) is critical for proton exchange membrane fuel cells (PEMFCs). Herein, high-entropy intermetallic (HEI) L12-Pt(FeCoNiCuZn)3 is designed for durable ORR catalysis. Benefiting from the unique HEI structure and the enhanced intermetallic phase stability, Pt(FeCoNiCuZn)3/C nanoparticles demonstrate significantly improved stability over Pt/C and PtCu3/C catalysts. The Pt(FeCoNiCuZn)3/C exhibits a negligible decay of the half-wave potential during 30,000 potential cycles from 0.6 to 1.0 V, whereas Pt/C and PtCu3/C are negatively shifted by 46 and 36 mV, respectively. Even after 10,000 cycles at potential up to 1.5 V, the mass activity of Pt(FeCoNiCuZn)3/C still shows -70% retention. As evidenced by the structural characterizations, the HEI structure of Pt(FeCoNiCuZn)3/C is well maintained, while PtCu3/C nanoparticles undergo severe Cu leaching and particle growth. In addition, when assembled Pt (FeCoNiCuZn)3/C as the cathode in high-temperature PEMFC of 160 degrees C, the H2-O2 fuel cell delivers almost no degradation even after operating for 150 h, demonstrating the potential for fuel cell applications. This work provides a facile design strategy for the development of high-performance ultrastable electrocatalysts. (c) 2023 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

This study presents the design of high-entropy intermetallic (HEI) L12-Pt(FeCoNiCuZn)3 as an electrocatalyst to enhance the stability of Pt-based cathodes for proton exchange membrane fuel cells (PEMFCs). The Pt(FeCoNiCuZn)3/C nanoparticles demonstrate significantly improved stability and activity compared to Pt/C and PtCu3/C catalysts. Moreover, the Pt(FeCoNiCuZn)+3/C catalyst exhibits excellent stability even under high-temperature conditions in fuel cells.