Conformal Shell Amorphization of Nanoporous Ag-Bi for Efficient Formate Generation.

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Achieving high conductivity and catalysis simultaneously in amorphous electrocatalysts for CO2 electroreduction (CO2ER) at high overpotentials is challenging.
• Nanoporous materials offer unique properties for catalysis but often face conductivity limitations.

Purpose of the Study:

• To develop a novel amorphous nanoporous silver-bismuth (a-NPSB) catalyst.
• To enhance both conductivity and catalytic activity for CO2ER.
• To investigate the structure-activity relationship of the a-NPSB catalyst.

Main Methods:

• Developed a protocol for shell amorphization of nanoporous Ag-Bi catalysts.
• Characterized the catalyst's structure and morphology.
• Evaluated catalytic performance for CO2 electroreduction, measuring Faradaic efficiency and current densities.

Main Results:

• The a-NPSB catalyst demonstrated excellent CO2ER performance, achieving 88.4% Faradaic efficiency for formate production at -1.15 V vs RHE.
• High specific current density (21.2 mA cm⁻²) and mass specific current density (321 mA mg⁻¹) were recorded.
• The enhanced performance is attributed to the synergistic effect of the conductive inner metal ligament and the amorphous Bi2O3 shell.

Conclusions:

• The novel a-NPSB catalyst successfully integrates high conductivity and superior catalytic activity for CO2ER.
• The findings provide a new strategy for designing robust electrodes for electrochemical reactions.
• This approach opens avenues for advanced electrocatalyst design for CO2 conversion.