Modeling of nanoporous phenolic resins and investigating their CO2 adsorption behavior via molecular dynamics simulation

Abstract

A new modeling method of nanoporous phenolic resins via molecular dynamics (MD) simulation using structure-modified zeolite-templated carbons (ZTCs) as a template was developed. The cross-linking reactions of phenols were simulated within spaces defined by the surfaces of triangulated and expanded ZTCs (xZTCs) using MD simulation. The resulting low-density, porous phenolic resins with 90 % conversion formed negative replicas of xZTCs, characterized by CO₂-accessible, three-dimensional nanochannels with diameters of 0.8–2.7 nm and a surface area exceeding 0.55 × 10³ m² g⁻¹. The nanochannels were structurally stable and did not collapse even under uniaxial unit cell deformation, and the elastic modulus of the porous resins was 2–3 GPa. The CO₂ molecules were inserted into the resin nanochannels and the partial CO₂ pressure was estimated by calculating the excess chemical potential. The simulated CO₂ adsorption isotherms followed the Henry’s isotherm model at a partial pressure below 7 kPa. This study demonstrates the applicability of the nanoporous phenolic resins modeled by the proposed method for the theoretical investigation of their CO₂ adsorption behavior in low partial pressure regions, which is relevant to direct air capture.