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Download fileTuning 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
journal contribution
posted on 18.08.2020, 07:13 authored by Md Ariful Ahsan, Alain R. Puente Santiago, Yu Hong, Ning Zhang, Manuel Cano, Enrique Rodriguez-Castellon, Luis Echegoyen, Sreeprasad T. Sreenivasan, Juan C. NoveronThe
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.
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Keywords
RuO 2 benchmark catalystSurface Compositionelectrocatalytic functionsHydrogen Evolution ReactionsRuO 2Local Structural Distortions20 000non-noble bimetallic nanostructuresexhibits trifunctionalsp 2 carbon frameworkbimetallic systemshydrogen evolutionNiCu nanoalloys0.25Pt catalysts1.44 V vs RHEbinding energy400 mVbinding energiesBimetallic nanosystemsbimetallic latticeOER performanceH 2Porous Carbon NetworkH 2 OHERO 2use non-noble metalsmultifunctional catalystsORRnanoparticle surfacesmultifunctional electrocatalytic pr...alloy nanoparticlesXPS analysisTrifunctional NiCu Bimetallic Nanop...electrocatalytic activity0.75Electrocatalytic Oxygen Reductionoxygen evolution