Unlocking cathodic potential dependent Pd deactivation for energy efficient CO₂ electroreduction to formate.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Palladium (Pd)-based materials excel as electrocatalysts for CO2 reduction to formate.
• However, Pd catalysts deactivate at high overpotentials, limiting formate production.
• Developing stable and active catalysts for CO2 electroreduction is crucial for sustainable energy solutions.

Purpose of the Study:

• To develop a novel palladium/fullerene (PdC60) composite catalyst for enhanced CO2 electroreduction to formate.
• To investigate the mechanism behind the improved performance and stability of the PdC60 catalyst.
• To demonstrate the practical applicability of the PdC60 catalyst in a membrane electrode assembly reactor.

Main Methods:

• Synthesis of a palladium/fullerene (PdC60) composite catalyst.
• Electrochemical characterization of the catalyst's performance in CO2 reduction.
• Operando mechanistic studies to understand charge transfer and deactivation pathways.
• Testing in a membrane electrode assembly reactor for practical current densities and energy efficiency.

Main Results:

• The PdC60 composite exhibited significantly improved activity and stability for CO2-to-formate conversion, even at high overpotentials.
• A current density of 250 mA cm-2 was achieved with 72% energy efficiency in a membrane electrode assembly reactor.
• Mechanistic studies revealed that interfacial charge transfer from Pd to C60 suppresses Pd-H phase transition and alleviates CO poisoning.

Conclusions:

• The PdC60 composite catalyst offers a promising solution for efficient and stable CO2 electroreduction.
• The findings highlight the importance of interfacial engineering in designing advanced electrocatalysts.
• This work advances the development of energy-efficient CO2 conversion technologies.