Interconnected nanoconfining pore networks enhance catalyst CO₂ interaction in electrified reactive capture

Area of Science:

• Electrochemistry
• Catalysis
• Carbon Capture and Utilization (CCU)

Background:

• CO2 capture and conversion to fuels is energy-intensive, particularly the CO2 release step.
• Electrified reactive capture systems convert CO2 from carbonate liquids into valuable products.
• Existing systems suffer from decreased Faradaic efficiency (FE) at high current densities (>200 mA/cm²).

Purpose of the Study:

• Investigate the chemical reasons for FE decline in previous reactive capture systems.
• Develop novel electrocatalyst designs to overcome limitations in CO2 activation and reduction.
• Enhance the efficiency of CO2 electrolysis for fuel production.

Main Methods:

• Developed a templated synthesis to create specific pore structures with single Ni atoms.
• Utilized carbon-nitrogen-based nanopores to accumulate and activate in situ-generated CO2 (i-CO2).
• Investigated short-range, non-electrostatic interactions for CO2 confinement and enrichment.

Main Results:

• Achieved carbonate electrolysis at 300 mA/cm² with 50% ± 3% FE to CO.
• Maintained <1% CO2 in the tailgas outlet stream.
• Projected energy efficiency (EE) to 2:1 syngas of 46% at 300 mA/cm² with H2 addition.

Conclusions:

• Novel carbon-nitrogen nanopores effectively capture, activate, and reduce i-CO2.
• The new catalyst design overcomes previous FE limitations at high current densities.
• This work presents a significant advancement in efficient CO2 conversion to fuels via electrolysis.