Effect of Different Oxygen-Containing Groups on the Nanopore Diameter of Hyper-Crosslinked Resins for Gas Adsorption/Separation

Few studies have been conducted on the effect of nonamine groups on the nanopore environment and gas adsorption/separation ability of normal spherical hyper-crosslinked resins. Here, hyper-crosslinked resins (HCP@COOH and HCP@CO), modified with a COOH-containing structure (A) and a C & boxH;O-containing structure (B), were synthesized by the Friedel-Crafts acylation reaction. According to static adsorption and dynamic separation tests, different oxygen-containing groups have different impacts on the nanopore diameter and small gas adsorption/separation behavior. Structure (A), benefiting from its suitable nanoscale size, was verified to be effective in narrowing the size of nanopores to 1-2 nm and increasing the adsorption capacity of CO2, CH4, and CO, while Structure (B) seems to have a positive influence only on CH4. The uptake of CO2 and the separation ratio of CO2/CO in HCP@COOH reach 32 cm(3)/g and 12.2, respectively, at 298 K and 1 bar. The IAST selectivity of CH4/CO in HCP@O-1 is up to 3.4, increasing from 1.9 for HCP-1. HCP@COOH can separate syngas efficiently at ambient temperature and can be regenerated by simple vacuum operation. The interaction mechanism was also analyzed by experiments and electrostatic potential simulation.