Copper Doping Boosts Electrocatalytic CO₂ Reduction of Atomically Precise Gold Nanoclusters

Area of Science:

• Nanocatalysis
• Electrocatalysis
• Materials Science

Background:

• Understanding nanoalloy synergistic effects is crucial for optimizing electrocatalytic CO2 reduction (eCO2RR).
• Lack of crystallographically defined structures hinders atomistic insights into bimetallic catalyst performance.

Purpose of the Study:

• To synthesize and characterize a AuCu nanoalloy cluster catalyst.
• To elucidate the atomistic synergistic effects of Au and Cu on eCO2RR.
• To compare the catalytic performance of the AuCu nanoalloy with a monometallic gold analogue.

Main Methods:

• One-pot synthesis of AuCu nanoalloy clusters.
• Single-crystal X-ray diffraction for structural characterization.
• Electrocatalytic performance evaluation in a gas diffusion electrode-based membrane electrode assembly (MEA) cell.
• Density Functional Theory (DFT) calculations.

Main Results:

• A well-defined AuCu nanoalloy cluster, [Au15Cu4(DPPM)6Cl4(C≡CR)]2+, was synthesized and structurally characterized.
• The AuCu nanoalloy catalyst achieved a high CO Faradaic efficiency (>90%) for eCO2RR, significantly outperforming the undoped Au catalyst (60%).
• An industrial-level CO partial current density of up to -413 mA/cm2 was achieved with the AuCu catalyst.
• DFT calculations revealed synergistic effects from Cu doping, highlighting dual AuCu sites responsible for enhanced catalysis.

Conclusions:

• The synthesized AuCu nanoalloy cluster is a highly efficient catalyst for electrocatalytic CO2 reduction.
• Cu doping in gold nanoalloys induces synergistic effects, enhancing catalytic activity and selectivity.
• The study provides atomistic insights into the mechanism of eCO2RR on bimetallic nanoalloys.