Performance and Mechanism Analysis of TiO₂-Modified Cross-Linked Resin in the Process of CO₂ Capture

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Amine-functionalized resins are promising for CO2 capture but suffer from amine degradation and poor cyclic stability.
• This limits their practical application in industrial carbon capture systems.

Purpose of the Study:

• To develop a stable and efficient CO2 adsorbent by modifying amine resins with TiO2 nanoparticles.
• To investigate the mechanism of TiO2's effect on amine stability and CO2 adsorption properties.

Main Methods:

• Synthesis of a TiO2-modified TEPA-supported spherical composite (TEPA-TiO2@SCPS) using a sol-gel method.
• Characterization using elemental analysis, XPS, SEM, XRD, and cyclic adsorption-desorption tests.
• Density Functional Theory (DFT) calculations to elucidate the adsorption mechanism.

Main Results:

• TiO2 modification significantly improved amine retention (81.5 wt% to 91.4 wt%) and reduced CO2 adsorption capacity loss over 10 cycles (1.5% vs 3.8% for unmodified resin).
• DFT calculations showed TiO2 lowers the CO2 adsorption energy barrier by 53.2% and facilitates reversible proton transfer.
• Enhanced structural stability and electron transfer attributed to TiO2 nanoparticles.

Conclusions:

• TiO2 modification effectively enhances the cyclic stability and CO2 capture efficiency of amine-based adsorbents.
• The study reveals TiO2's role in modulating amine reactivity and structural integrity at a molecular level.
• This provides a promising strategy for developing robust amine adsorbents for long-term CO2 capture applications.