Efficient CO₂ Capture Using Nitrogen-Enriched Microporous Carbon Derived from Polybenzoxazine in a Single-Step...

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Developing efficient adsorbents for carbon dioxide (CO2) capture is crucial for mitigating climate change.
• Microporous carbon materials offer high surface areas and tunable properties for gas adsorption.
• Nitrogen doping can enhance the CO2 adsorption capacity of carbon materials through chemical interactions.

Purpose of the Study:

• To synthesize nitrogen-enriched microporous carbon from polybenzoxazine using distinct activation methods.
• To investigate the impact of activation agents (KOH and KMnO4) on the material's porosity and surface area.
• To evaluate the CO2 adsorption performance of the synthesized material.

Main Methods:

• Polybenzoxazine was carbonized at 800 °C to form a precursor.
• The precursor was activated using KOH and KMnO4 at 800 °C.
• X-ray Photoelectron Spectroscopy (XPS) was used to analyze nitrogen functionalities.
• CO2 adsorption isotherms were measured at 25 °C and 1 bar.

Main Results:

• Activation with KMnO4 yielded a significantly higher surface area (943 m²/g) compared to KOH (335 m²/g).
• XPS confirmed the presence of various nitrogen functionalities (secondary-N, oxide-N, pyridone-N, pyridine-N).
• The material achieved a high CO2 uptake of 3.8 mmol/g at 25 °C and 1 bar.

Conclusions:

• Nitrogen-enriched microporous carbon derived from polybenzoxazine demonstrates excellent CO2 adsorption capacity.
• The high performance is attributed to the synergistic effects of high surface area, microporosity, and nitrogen doping.
• This material shows significant potential for practical CO2 capture and storage applications.