Highly Stable Single-Phase FeCoNiMnX (X = Cr, Mo, W) High-Entropy Alloy Catalysts with Submicrometer Size for Efficient Oxygen Evolution
Peng Li, Bozhao Wu, Kaifa Du, Ze Liu, Enlai Gao, Huayi Yin, Dihua Wang
Abstract
The activity and stability of oxygen evolution reaction (OER) catalysts are often trade-offs and are both size-dependent. Theoretical calculations have predicted that some noble-metal-free high-entropy alloys (HEAs) are promising OER catalysts. However, their catalytic properties have not been proven because of the lack of a facile method to synthesize small-sized homogeneous HEA particles. Here, submicrometer-sized single-phase FeCoNiMnW HEA particles were prepared by electrochemical metallization in 900 s (at 900 °C). FeCoNiMnW shows the best OER activity (η = 355 mV at 500 mA cm –2 ) and durability of the three HEAs because the large total density of states of FeCoNiMnW accelerates the electrons’ transport speed for OER. More importantly, the single-phase FeCoNiMnW continuously operated for 50 days at 500 mA cm –2 with an almost unchanged overpotential. Overall, this work offers a rapid and simple method to prepare various effective and long-lasting single-phase HEA catalysts with controllable sizes and enhanced OER performances.