CH₃COOK Etching to Prepare N-Doped Peanut Shell Microporous Carbon for Efficient CO₂ Adsorption

Area of Science:

• Materials Science
• Environmental Chemistry
• Chemical Engineering

Background:

• Growing concerns over atmospheric CO2 levels necessitate advanced carbon capture technologies.
• Biomass-derived porous carbons offer a sustainable and cost-effective alternative for CO2 adsorption.

Purpose of the Study:

• To synthesize and characterize novel microporous nitrogen-doped porous carbons (NPSCs) from peanut shells.
• To optimize the synthesis parameters for enhanced CO2 adsorption performance.
• To evaluate the stability and selectivity of the synthesized materials for carbon capture.

Main Methods:

• A two-step synthesis method involving carbonization and activation.
• Utilizing peanut shells as the carbon source, urea as the nitrogen source, and potassium acetate (CH3COOK) as the activating agent.
• Optimization of activating agent ratio and carbonization temperature.

Main Results:

• Successfully synthesized N-doped porous carbons with a high density of micropores.
• The optimal sample (NPSC-2-700) achieved a specific surface area of 1455.41 m2/g and a micropore volume of 0.57 cm3/g.
• NPSC-2-700 exhibited excellent CO2 adsorption capacities (3.91 mmol/g at 25°C, 5.90 mmol/g at 0°C) and selectivity (43 for CO2/N2).
• The material demonstrated remarkable stability over ten adsorption-desorption cycles.

Conclusions:

• The developed N-doped porous carbons from biomass are highly effective for CO2 capture.
• The optimized pore structure and nitrogen doping significantly enhance adsorption capacity and selectivity.
• These materials show great promise for practical applications in carbon capture technologies.