Hyper-Crosslinked Resins Modified by Ferrocene for CO₂/CO and CO₂/CH₄ Separation

The morphology and regeneration ability of adsorbents are important for gas pressure swing adsorption and separation. Herein, HCP-1 (a hyper-crosslinked polymer) and HCP@MAO(Fe) (a hyper-crosslinked polymer modified by ferrocene) with a spherical morphology are synthesized by a post-crosslinking reaction of chloromethylated styrene-divinylbenzene (Cl-St-DVB) beads for the separation of CO2/CO and CO2/CH4. Both static adsorption and dynamic separation tests verified that HCP@MAO(Fe) has the best gas adsorption and separation performance. The highest adsorption capacity of CO2 reached 1.24 mmol/g. The IAST selectivity of CO2/CO is up to 20.6. Moreover, HCP@MAO(Fe) can be regenerated by simple vacuum operation, contributing to the low value of adsorption enthalpy (24.5 KJ/mol). The adsorption mechanism between CO2 and the resin framework was also studied by experiments and electrostatic potential map analysis. A stronger interaction can be found between CO2 and HCP@MAO(Fe) as a result of the higher Mulliken charge of the cyclopentadiene structure.