Identifying the Point of Attachment in the Hypercrosslinking of Benzene for the Synthesis of a Nanoporous Polymer as a Superior Adsorbent for High-Pressure CO₂ Capture Application

The point of attachment in the hypercrosslinking of benzene using formaldehyde dimethyl acetal as the crosslinker, anhydrous ferric chloride as the catalyst, and 1,2 dichloroethane as the solvent for the synthesis of poly-benz is reported. A fast microwave-assisted synthesis, within a reaction time of 60 min, resulted in the formation of nanoporous poly-benz having a specific surface area of 1168 m2 g–1. A thorough analysis of poly-benz using 13C cross-polarization magic angle spinning nuclear magnetic resonance and X-ray photoelectron spectra has revealed the hypercrosslinking at the meta position of the benzene ring. The synthesized poly-benz further shows a high CO2 capture capacity of 65.3 wt % at 298 K and 30 bar. Various adsorption isotherm models have been fitted at different temperatures up to 30 bar to represent the equilibrium CO2 adsorption data.