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 ultrasmall (~3.4 nm) high-entropy alloys (HEAs) Pt18Ni26Fe15Co14Cu27 nanoparticles are synthesized by a simple low-temperature oil phase strategy at atmospheric pressure. The Pt18Ni26Fe15Co14Cu27/C catalyst exhibits excellent electrocatalytic performance for hydrogen evolution reaction (HER) and methanol oxidation reaction (MOR). The catalyst shows 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 efficient catalyst (15.04 A mg−1Pt) ever reported for MOR in alkaline solution. Periodic 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.

High-entropy materials for catalysis: A new frontier

“…Alloying Pt (or Pd) with other metal species modulates the electronic structure and weakens the binding of the CO-like intermediates and thus alleviates the related poisoning effect. In another study, Li et al ( 106 ) prepared the Pt 18 Ni 26 Fe 15 Co 14 Cu 27 HEA nanoparticles, which exhibited remarkable methanol oxidation activities and enhanced CO antipoisoning in alkaline solutions. Using DFT calculations, the authors analyzed the partial projected density of states of each element upon methanol adsorption and revealed an efficient site-to-site electron transfer process.…”

Solvent-free microwave synthesis of ultra-small Ru-Mo2C@CNT with strong metal-support interaction for industrial hydrogen evolution

“…At present, platinum (Pt)-based catalyst is the best hydrogen evolution catalyst, but the low natural content of Pt and its high price limit its large-scale production 10 – 12 . The design and development of high-performance and low-cost catalysts with low precious metal loading catalysts have become the top priority in this field 13 – 15 . Ruthenium (Ru), due to its low cost (only 1/3 of the price of Pt) and high activity (the Gibbs free energy (ΔG H ) of Ru–H bond is very close to the free energy of Pt–H bond in the center of HER volcanic map), so it has become one of the cheap substitutes for Pt 16 , 17 .…”

Nanoporous ultra-high-entropy alloys containing fourteen elements for water splitting electrocatalysis

“…Rational optimization of the composition and geometric structure of HEAs is essential for improving their catalytic activity; however, to the best of our knowledge, the development of facile and controlled syntheses of nanoscale HEA-based catalysts is still in its infancy. Several techniques have been reported for constructing nanostructured HEAs intended for heterogeneous catalysis, including the carbothermal shock technique, 14,15 mechanical alloying, 16 fast moving bed pyrolysis, 17 chemical synthesis, 18–20 and dealloying. 21–24 Among these methods, dealloying is an electrochemical process commonly employed for the selective dissolution of less stable elements from precursor alloys.…”