Tuning of Trifunctional NiCu Bimetallic Nanoparticles Confined in a Porous Carbon Network with Surface Composition and Local Structural Distortions for the Electrocatalytic Oxygen Reduction, Oxygen and Hydrogen Evolution Reactions

Abstract

The rational design of multifunctional catalysts that use non-noble metals to facilitate the interconversion between H2, O2, and H2O is an intense area of investigation. Bimetallic nanosystems with highly tunable electronic, structural, and catalytic properties that depend on their composition, structure, and size have attracted considerable attention. Herein, we report the synthesis of bimetallic nickel–copper (NiCu) alloy nanoparticles confined in a sp2 carbon framework that exhibits trifunctional catalytic properties toward hydrogen evolution (HER), oxygen reduction (ORR), and oxygen evolution (OER) reactions. The electrocatalytic functions of the NiCu nanoalloys were experimentally and theoretically correlated with the composition-dependent local structural distortion of the bimetallic lattice at the nanoparticle surfaces. Our study demonstrated a downshift of the d-band of the catalysts that adjusts the binding energies of the intermediate catalytic species. XPS analysis revealed that the binding energy for Ni 2p3/2 band of the Ni0.25Cu0.75/C nanoparticles was shifted ∼3 times compared to other bimetallic systems, and this was correlated to the high electrocatalytic activity observed. Interestingly, the bimetallic Ni0.25Cu0.75/C catalyst surpassed the OER performance of RuO2 benchmark catalyst exhibiting a small onset potential of 1.44 V vs RHE and an overpotential of 400 mV at 10 mA·cm–2 as well as the electrochemical long-term stability of commercial RuO2 and Pt catalysts and kept at least 90% of the initial current applied after 20 000 s for the OER/ORR/HER reactions. This study reveals significant insight about the structure–function relationship for non-noble bimetallic nanostructures with multifunctional electrocatalytic properties.

N, S Codoped Carbon Matrix‐Encapsulated Co9S8 Nanoparticles as a Highly Efficient and Durable Bifunctional Oxygen Redox Electrocatalyst for Rechargeable Zn–Air Batteries

“…Furthermore, a wide range of comparisons shows that the as‐prepared Co 9 S 8 @N, S–C catalyst is better than most of the highly performing bifunctional catalysts reported so far (see Table S1 in the Supporting Information for a detailed comparison). [ 10,27–49 ]…”

Recent Advances of CeO2‐Based Electrocatalysts for Oxygen and Hydrogen Evolution as well as Nitrogen Reduction

“…Of course, except for cobalt, other transition metals such as nickel and iron are also good candidates towards OER. [38][39][40] In addition, cerium oxide has the general characteristics of metal oxide, high temperature resistance and high stability. The surface dangling oxygen species makes it feasible to hybrid metals with CeO 2 to fabricate CeO 2 /metal composite catalysts.…”

“…Therefore, it can be deemed that the combination of cobalt and CeO 2 can give rise to better electrocatalytic performance. Of course, except for cobalt, other transition metals such as nickel and iron are also good candidates towards OER [38–40] . In addition, cerium oxide has the general characteristics of metal oxide, high temperature resistance and high stability.…”

1T-MoS2 Coordinated Bimetal Atoms as Active Centers to Facilitate Hydrogen Generation

“…The electrocatalytic hydrogen evolution reaction (HER: 2H + + 2e − → H 2 ) is the key to achieve clean hydrogen energy [ 1 , 2 ]. Highly active and stable electrocatalysts are required to drive the sluggish thermodynamic and kinetic processes of HER [ 3 ]. Until now, Pt/C is the benchmark catalyst for hydrogen production [ 4 ].…”