Fast Site-to-site Electron Transfer of High-entropy Alloy Nanocatalyst Driving Redox Electrocatalysis

Abstract

Designing electrocatalysts with high-performance for both reduction and oxidation reactions faces severe challenges. Here, the uniform and small size (~3.4 nm) high-entropy alloys (HEAs) Pt18Ni26Fe15Co14Cu27 nanoparticles (NPs) are synthesized by a simple low-temperature (<250 oC) oil phase synthesis strategy at atmospheric pressure for the first time. The Pt18Ni26Fe15Co14Cu27/C catalyst exhibits excellent electrocatalytic performance for hydrogen evolution reaction (HER) and methanol oxidation reaction (MOR). The catalyst is one of the best performance achieved by state-of-the-art alkaline HER catalysts, which shows an ultrasmall overpotential of 11 mV at the current density of 10 mA cm-2, excellent activity (10.96 A mg-1Pt at -0.07 V vs. reversible hydrogen electrode) and stability in the alkaline medium. Furthermore, it is also the most efficient catalyst (15.04 A mg-1Pt) ever reported for MOR in alkaline solution. DFT calculations confirm the multi-active sites for both HER and MOR on the HEA surface as the key factor for both proton and intermediate transformation. Meanwhile, the construction of HEA surfaces supplies the fast site-to-site electron transfer for both reduction and oxidation processes.

Designing strategies and enhancing mechanism for multicomponent high-entropy catalysts

“…2e and f). 49 The catalyst shows an ultrasmall overpotential of 11 mV at 10 mA cm −2 for the HER and 15.04 A mg Pt −1 is achieved for the methanol oxidation reaction (MOR) in alkaline media (Fig. 2g).…”

Recent advances in surface reconstruction toward self-adaptive electrocatalysis: a review

“…In this regard, high-entropy metal alloys (≥5 metals) with broader compositional tunability are ideal candidates for the cycle; they can be designed for the optimal adsorption/reaction of intermediates via multipleelemental synergy and thus boost electrocatalytic efficiency in accordance with the Sabatier principle. 78,79 In addition, the high-entropy nature facilitates the stabilization of the alloy phase and inhibits the movement of dislocations, thereby increasing the catalyst stability with a longer cycle period for maximizing the self-adaptive electrocatalysis efficiency. The development of electrochemical approaches for the in situ synthesis of high-entropy metal alloys is essential for cycle applications.…”