Polyethyleneimine-crosslinked cellulose aerogel for combustion CO₂ capture

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Polyethylenimine (PEI) is often used for CO2 adsorption but can block pores in solids.
• This pore blockage limits the practical application of PEI-based sorbents.
• A new approach is needed to overcome PEI's limitations in CO2 capture materials.

Purpose of the Study:

• To develop a novel polyethyleneimine-crosslinked cellulose (PCC) aerogel for CO2 adsorption.
• To investigate the structural properties and CO2 adsorption performance of the PCC aerogel.
• To evaluate the recyclability and adsorption mechanism of the PCC aerogel.

Main Methods:

• Preparation of PCC aerogel via sol-gel, hydrolysis, and crosslinking reactions.
• Characterization of the PCC aerogel's specific surface area and nitrogen content.
• Measurement of CO2 adsorption capacity and analysis of adsorption kinetics and diffusion mechanisms.

Main Results:

• The PCC aerogel maintained a high specific surface area (234.2 m²/g) with 17.4 wt% nitrogen.
• Achieved a CO2 adsorption capacity of 2.31 mmol/g at 25 °C under dry conditions.
• The pseudo-second-order model accurately described adsorption kinetics, indicating both intra-particle and surface diffusion limitations.
• Demonstrated excellent recyclability over 10 adsorption-desorption cycles.

Conclusions:

• The PCC aerogel is a promising solid sorbent for CO2 capture.
• The crosslinking strategy effectively prevents pore blockage by PEI.
• The material exhibits high adsorption capacity, good recyclability, and a well-defined adsorption mechanism.