Microwave heating-assisted synthesis of ultrathin platinum-based trimetallic nanosheets as highly stable catalysts towards oxygen reduction reaction in acidic medium.

[Display omitted] There are currently almost no ternary platinum-based nanosheets used for acidic oxygen reduction reactions (ORR) due to the difficulty in synthesizing ternary nanosheets with high Pt content. In this work, several ultrathin platinum-palladium-copper nanosheets (PtPdCu NSs) with a thickness of around 1.90 nm were prepared via a microwave heating-assisted method. Microwave heating allows a large number of Pt atoms to deposit into PdCu nanosheets, forming Pt-based ternary nanosheets with high Pt content. Among them, Pt 38 Pd 50 Cu 12 NSs catalyst displays the highest mass activity (MA) measured in 0.1 M HClO 4 of 0.932 A/mg Pt+Pd which is 8.6 times of that Pt/C. Besides, Pt 38 Pd 50 Cu 12 NSs catalyst also exhibits excellent stability with an extremely low MA attenuation after 80,000 cycles accelerated durability testing (ADT) tests. In the single cell tests, the Pt 38 Pd 50 Cu 12 NSs catalyst manifests higher maximum power density of 796 mW cm−2 than Pt/C of 606 mW cm−2. Density functional theory (DFT) calculations indicate the weaker adsorption between Pt and O-species in Pt 38 Pd 50 Cu 12 NSs leads to a significant enhancement of ORR activity. This study provides a new strategy to design and prepare ultrathin Pt-based trimetallic nanosheets as efficient and durable ORR catalysts. [ABSTRACT FROM AUTHOR]