Synthesis of amine-pillar[5]arene porous adsorbent for adsorption of CO2 and selectivity over N2 and CH4

Abstract

A novel amine-modified pillar[5]arene bonded porous silica adsorbent (DETA-P5S) was designed to be applied to dynamic CO2 adsorption and selective separation of CO2 over N2 and CH4 gases mixture. The results demonstrated that reasonable introduction of DETA into the BE-P5 bonded silica support has significantly increased the adsorption capacity of CO2. The DETA-P5S has the optimal adsorption capacity of 9.1 mmol/g with 5 vol% CO2 at 40 °C. The main reason of this increased capacity could be attributed to the enhanced CO2 diffusion into porous adsorbent for its better dispersion in the pores of amine-pillar[5]arene cavity and active site of DETA. Furthermore, the dynamic saturation adsorption capacities of DETA-P5S were 7.11 (0.37) and 6.18 (0.44) mmol/g for CO2/N2 and CO2/CH4, respectively, both the gas mixtures showed high separation selectivity. Simultaneously, the DETA-P5S can maintain outstanding CO2 adsorption capacity after fifteen regeneration cycles. Consequently, the designed DETA-P5S could serve as a promising adsorbent for CO2 capture and storage.