Strained Lattice Gold-Copper Alloy Nanoparticles for Efficient Carbon Dioxide Electroreduction.

Area of Science:

• Catalysis
• Materials Science
• Electrochemistry

Background:

• Carbon dioxide (CO₂) conversion into renewable fuels is crucial for mitigating climate change and addressing energy demands.
• Developing efficient electrocatalysts is key to achieving selective CO₂ reduction.

Purpose of the Study:

• To synthesize and characterize tunable gold-copper alloy nanoparticles (Au_nCu_100-n/C NPs) for CO₂ electrocatalytic reduction.
• To investigate the relationship between alloy composition, lattice strain, crystal plane, and catalytic activity.

Main Methods:

• Synthesis of Au_nCu_100-n/C alloy nanoparticles using a thermal solvent co-reduction method.
• Characterization using Transmission Electron Microscopy (TEM) and X-ray Diffraction (XRD).
• Electrochemical evaluation of CO₂ reduction activity and selectivity.

Main Results:

• Au_nCu_100-n/C catalysts exhibited tunable compositions, subtle lattice strain, and a dominant (111) crystal plane.
• The Au₇₅Cu₂₅/C catalyst demonstrated high catalytic activity for CO₂ reduction.
• A maximum Faradaic efficiency of 92.6% for CO was achieved at -0.7 V (vs. RHE) for Au₇₅Cu₂₅/C.

Conclusions:

• The observed high catalytic activity is attributed to lattice shrinkage and the specific active facet of the alloy nanoparticles.
• This study presents a novel strategy for designing robust and active nanoalloy catalysts for CO₂ reduction by controlling lattice mismatch and dominant active surfaces.