Edge-functionalized nanoporous carbons for high adsorption capacity and selectivity of CO2 over N2

Single-component adsorption and competitive behavior of binary CO2/N-2 mixture in the edgefunctionalized nanoporous carbons (NPCs) were investigated by grand canonical Monte Carlo simulation. Results demonstrated that edge-functionalization effectively improved the pore topology and morphological characteristics of NPCs. Evaluation of adsorption capacity and analyses of the isosteric heat and radial distribution functions confirmed that edge-functionalization can evidently enhance the single-component adsorption of CO2/N-2. Temperature had a negative effect on the single-component adsorption of CO2/N-2 whereas pressure had a positive effect before adsorption reaches a stable equilibrium state. Edge-functionalization can significantly increase the selectivity of CO2 over N-2 in NPCs, which demonstrate the following sequence according to selectivity: NH2-NPC > COOH-NPC > OH-NPC > H-NP C> NPC. The increased CO2 molar fraction in the binary CO2/N-2 mixture decreased the selectivity and saturation pressure to reach a stable equilibrium state. Overall, this work highlighted the effects of edge-functionalization on the adsorption and separation of CO2/N-2 in NPCs, and provided an effective strategy for designing and screening adsorbent materials for carbon capture and separation. (C) 2017 Elsevier B.V. All rights reserved.