Adsorption Kinetics for CO2 Capture using Cerium Oxide Impregnated on Activated Carbon

Area of Science:

• Materials Science
• Environmental Chemistry
• Chemical Engineering

Background:

• Growing concerns about atmospheric carbon dioxide (CO2) levels necessitate the development of efficient CO2 capture technologies.
• Metal oxides supported on porous materials are promising adsorbents for CO2 removal due to their tunable properties and high surface area.

Purpose of the Study:

• To synthesize and evaluate various metal oxides (CeO2, ZnO, Co3O4) impregnated on activated carbon (AC) for CO2 capture efficiency.
• To analyze the adsorption kinetics and performance of the most effective adsorbent over multiple adsorption-desorption cycles.

Main Methods:

• Synthesis of metal oxides (CeO2, ZnO, Co3O4) on activated carbon (AC).
• Batch kinetic studies for CO2 adsorption experiments.
• Analysis using X-ray diffraction (XRD) and scanning electron microscopy (SEM).
• Adsorption kinetics modeling (pseudo-second-order) and error analysis.

Main Results:

• CeO2/AC demonstrated the highest CO2 capture efficiency, achieving an adsorption capacity of 52.68 mg/g with an equilibrium time of 10 minutes.
• Optimal adsorption temperature was found to be 30 °C, with minimal capacity loss (6.53%) after 5 adsorption-desorption cycles.
• XRD and SEM confirmed the presence and uniform distribution of CeO2 particles on the AC surface.
• Adsorption followed pseudo-second-order kinetics (R² = 0.9994) with low error (1.32%), indicating chemisorption as the primary mechanism.

Conclusions:

• CeO2/AC is a highly efficient adsorbent for CO2 capture, offering rapid adsorption and good recyclability.
• Chemisorption, facilitated by the active sites provided by CeO2 on AC, significantly enhances CO2 adsorption capacity.
• The developed CeO2/AC material shows potential for practical CO2 capture applications.