Balancing Activity and Stability through Compositional Engineering of Ternary PtNi-Au Alloy ORR Catalysts

Xie X, Briega-Martos V, Alemany P, Mohandas Sandhya AL, Skála T, Rodríguez MG, Nováková J, Dopita M, Vorochta M, Bruix A, Cherevko S, Neyman KM, Matolínová I, Khalakhan I (2024)

Publication Type: Journal article

Publication year: 2024

Journal

ACS Catalysis American Chemical Society

Pages Range: 234-245

DOI: 10.1021/acscatal.4c05269

Abstract

Achieving the optimal balance between cost-efficiency and stability of oxygen reduction reaction (ORR) catalysts is currently among the key research focuses aiming at reaching a broader implementation of proton-exchange membrane fuel cells (PEMFCs). To address this challenge, we combine two well-established strategies to enhance both activity and stability of platinum-based ORR catalysts. Specifically, we prepare ternary PtNi-Au alloys, where each alloying element plays a distinct role: Ni reduces costs and boosts ORR activity, while Au enhances stability. A systematic comparative analysis of the activity-stability relationship for compositionally tuned PtNi-Au model layers, prepared by magnetron co-sputtering, was conducted using a diverse range of complementary characterization techniques and electrochemistry, supported by density functional theory calculations. Our study reveals that a progressive increase of the Au concentration in the Pt50Ni50 alloy from 3 to 15 at % leads to opposing catalyst activity and stability trends. Specifically, we observe a decrease in the ORR activity accompanied by an increase in catalyst stability, manifested in the suppression of both Pt and Ni dissolution. Despite the reduced activity compared to PtNi, the PtNi-Au alloy with 15 at % Au still exhibits nearly three times the activity of monometallic Pt. It also demonstrates a significantly improved dissolution stability relative to that of the PtNi alloy and even monometallic Pt. These findings provide valuable insights into the intricate balance between activity and stability in multimetallic ORR catalysts, paving the way for the design of cost-effective and durable materials for PEMFCs.

Involved external institutions

Univerzita Karlova v Praze / Charles University in Prague CZ Czech Republic (CZ) Universitat de Barcelona (UB) / University of Barcelona ES Spain (ES) Forschungszentrum Jülich / Research Centre Jülich (FZJ) DE Germany (DE)

How to cite

APA:

Xie, X., Briega-Martos, V., Alemany, P., Mohandas Sandhya, A.L., Skála, T., Rodríguez, M.G.,... Khalakhan, I. (2024). Balancing Activity and Stability through Compositional Engineering of Ternary PtNi-Au Alloy ORR Catalysts. ACS Catalysis, 234-245. https://doi.org/10.1021/acscatal.4c05269

MLA:

Xie, Xianxian, et al. "Balancing Activity and Stability through Compositional Engineering of Ternary PtNi-Au Alloy ORR Catalysts." ACS Catalysis (2024): 234-245.

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