Functionalized Ag with Thiol Ligand to Promote Effective CO₂ Electroreduction

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrocatalytic CO2 reduction (CO2R) is crucial for sustainable energy, but achieving high current density and energy efficiency simultaneously remains challenging.
• Developing advanced catalysts is critical for efficient CO2 conversion into valuable products.

Purpose of the Study:

• To improve the intrinsic activity, selectivity, and energy efficiency of silver (Ag) catalysts for CO2R.
• To explore the effect of surface electronic structure modification using thiol ligands on catalyst performance.

Main Methods:

• Synthesized interconnected Ag nanoparticles with residual thiol ligands via electrochemical activation of a thiol-ligand-based Ag complex.
• Investigated CO2 reduction performance using the modified Ag catalyst.
• Performed first-principle calculations to understand reaction energetics and intermediate binding.

Main Results:

• The thiol-ligand modified Ag catalyst demonstrated high CO selectivity (>90%) over a wide potential range.
• Achieved high cathodic energy efficiencies (>90% at 150 mA cm-2 and >70% at 750 mA cm-2) for CO formation.
• Outperformed state-of-the-art Ag-based electrocatalysts in CO2 to CO conversion.

Conclusions:

• Surface electronic structure modulation via thiol ligands optimizes the binding of key intermediates, favoring CO formation.
• This strategy effectively suppresses competing hydrogen evolution reactions.
• Provides a rational design approach for developing highly efficient CO2 reduction electrocatalysts through electronic modulation.