Analysis of SO₂ Physisorption by Edge-Functionalized Nanoporous Carbons Using Grand Canonical Monte Carlo Methods and...

Nanoporous carbons (NPCs) are ideal materials for the dry process of flue gas desulfurization (FGD) due to their rich pore structure and high specific surface area. To study the effect of edge-functionalized NPCs on the physisorption mechanism of sulfur dioxide, different functional groups were embedded at the edge of NPCs, and the physisorption behavior was simulated using the grand canonical Monte Carlo method (GCMC) combined with density functional theory (DFT). The results indicated that the insertion of acidic oxygenous groups or basic nitrogenous groups into NPCs could enhance the physisorption of SO₂. The influence of edge functionalization on the pore structure of NPCs is also analyzed. To further explore the interaction in the adsorption process, the van der Waals (vdW) interaction and electrostatic interaction between the SO₂ molecule and the basic structural unit (BSU) were investigated. Simulated results showed that edge functionalization had limited influence on vdW interaction and did not significantly change the distribution characteristics of vdW interaction. According to the study on electrostatic interaction, edge functionalization was found to promote inhomogeneity of the surface charge of the adsorbent, enhance the polarity of the adsorbent, and thus enhance the physisorption capacity of SO₂. More importantly, we provide an idea for studying the difference in adsorption capacity caused by different functional groups connected to carbon adsorbents.