Mesopore-Augmented Electrochemical CO₂ Reduction on Nitrogen-Doped Carbon

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrochemical carbon dioxide reduction (eCO2RR) is key for carbon neutrality.
• Nitrogen-doped carbon (N-C) materials show promise for eCO2RR.
• Controlling N-C material porosity is crucial for catalytic performance and suppressing hydrogen evolution reaction (HER).

Purpose of the Study:

• To selectively enhance the mesoporous structure of N-C catalysts.
• To decouple the effect of mesoporosity from other compositional changes on eCO2RR performance.
• To investigate the role of mesopores in improving catalytic activity and selectivity.

Main Methods:

• Utilized a nanocasting approach with secondary carbon sources incorporated into a metal-organic framework (MOF) precursor.
• Synthesized N-C catalysts with controlled mesoporosity.
• Evaluated catalytic performance using electrochemical techniques, including Faradaic efficiency (FE) measurements for carbon monoxide (CO) production.

Main Results:

• The developed N-C catalyst exhibited a high surface area and abundant mesopores.
• Achieved a maximum Faradaic efficiency (FE) of 95% for carbon monoxide (CO) at -0.50 V vs. RHE.
• Demonstrated enhanced CO FE across a wide potential range, outperforming existing metal-free N-C catalysts.

Conclusions:

• Constructing mesoporous structures in N-C catalysts significantly enhances CO2 catalysis.
• Improved mesoporosity increases active site accessibility and elevates local pH, boosting CO2 reduction.
• This approach offers a promising strategy for developing efficient and cost-effective catalysts for eCO2RR.