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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.

Authors :
Ahsan MA
Puente Santiago AR
Hong Y
Zhang N
Cano M
Rodriguez-Castellon E
Echegoyen L
Sreenivasan ST
Noveron JC
Source :
Journal of the American Chemical Society [J Am Chem Soc] 2020 Aug 26; Vol. 142 (34), pp. 14688-14701. Date of Electronic Publication: 2020 Aug 18.
Publication Year :
2020

Abstract

The rational design of multifunctional catalysts that use non-noble metals to facilitate the interconversion between H <subscript>2</subscript> , O <subscript>2</subscript> , and H <subscript>2</subscript> O 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 sp <superscript>2</superscript> 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 2p <subscript>3/2</subscript> band of the Ni <subscript>0.25</subscript> Cu <subscript>0.75</subscript> /C nanoparticles was shifted ∼3 times compared to other bimetallic systems, and this was correlated to the high electrocatalytic activity observed. Interestingly, the bimetallic Ni <subscript>0.25</subscript> Cu <subscript>0.75</subscript> /C catalyst surpassed the OER performance of RuO <subscript>2</subscript> benchmark catalyst exhibiting a small onset potential of 1.44 V vs RHE and an overpotential of 400 mV at 10 mA·cm <superscript>-2</superscript> as well as the electrochemical long-term stability of commercial RuO <subscript>2</subscript> 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.

Details

Language :
English
ISSN :
1520-5126
Volume :
142
Issue :
34
Database :
MEDLINE
Journal :
Journal of the American Chemical Society
Publication Type :
Academic Journal
Accession number :
32786805
Full Text :
https://doi.org/10.1021/jacs.0c06960