Constructing Atomic-Level Defect as the Catalytic Site by Removing a Single Metal Atom from the Nanoclusters

Area of Science:

• Nanomaterials Science
• Catalysis
• Surface Engineering

Background:

• Gold clusters are promising catalysts, but their activity is sensitive to structural modifications.
• Understanding structure-activity relationships is crucial for designing efficient catalysts.

Purpose of the Study:

• To engineer a single-atom defect in a gold cluster.
• To investigate the impact of this defect on catalytic performance in electrochemical carbon dioxide reduction.

Main Methods:

• Surface engineering of Au₂₁(AdmS)₁₃S(F₃Ph₃P) to create Au₂₀(AdmS)₁₄(PhPy₂P).
• Structural analysis and comparison of the Au₂₁ and Au₂₀ clusters.
• Electrocatalytic evaluation of both clusters for the electrochemical carbon dioxide reduction reaction (eCO₂RR).

Main Results:

• The removal of the 21st gold atom exposed the 9th gold atom in the core, creating a catalytically active site.
• The defective Au₂₀ cluster showed significantly higher catalytic activity than the pristine Au₂₁ cluster in eCO₂RR.
• Au₂₀ achieved a current density 3 times higher than Au₂₁ at -1.3 V and a maximum Faradaic efficiency for CO (FE_CO) of 92.47% at -0.9 V, compared to 53.66% for Au₂₁.

Conclusions:

• Surface engineering to introduce atomic-level defects is an effective strategy to enhance gold cluster catalysis.
• The exposed core gold atom in the defective Au₂₀ cluster is key to its improved CO₂ adsorption and reduction.
• Theoretical calculations confirm enhanced charge transfer at the active site, promoting CO₂ reduction.