Ionic Liquids Modulating Local Microenvironment of Ni-Fe Binary Single Atom Catalyst for Efficient Electrochemical...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Dual-atom catalysts, like NiFe-N-C, suffer performance loss under high current densities.
• Optimizing the catalyst's microenvironment is crucial for enhancing CO2 electroreduction (CO2 ECR).

Purpose of the Study:

• To investigate the use of ionic liquids for modifying NiFe-N-C catalysts.
• To improve the stability and efficiency of CO2 ECR using tailored catalyst microenvironments.

Main Methods:

• Impregnation of nitrogen-doped carbon supported Ni and Fe dual-atom sites catalyst (NiFe-N-C) with various ionic liquids.
• Electrochemical characterization and theoretical calculations to analyze catalyst performance and mechanisms.
• Assembly of modified catalysts into Zn-CO2 batteries to assess practical applications.

Main Results:

• Ionic liquids enhance CO2 adsorption and stabilize the CO2 anion radical (CO2•¯), lowering the onset potential.
• BMImPF6-modified NiFe-N-C (NiFe-N-C/BMImPF6) achieved 91.9% CO faradaic efficiency at -1.0 V.
• The modified catalyst delivered a peak power density of 2.61 mW cm⁻² in a Zn-CO2 battery with excellent cycling stability.

Conclusions:

• Ionic liquids effectively regulate the microenvironment of dual-atom catalysts for superior CO2 ECR.
• The NiFe-N-C/BMImPF6 catalyst demonstrates high efficiency and stability for CO2 conversion.
• This approach offers a promising strategy for developing advanced catalysts for CO2 electroreduction and energy storage applications.