乙二胺不同掺杂模式下多孔有机聚合物对CO₂的吸附

Porous organic polymers (POPs), with high surface areas and well-developed porosities, were always deemed to be ideal candidates as the adsorbents for CO₂ capture. It is popular to introduce amino groups, the CO₂ chemisorptive sites, onto the POPs for improving the CO₂ capture capacities and selectivities of the POPs.In this study, ethylenediamine (EDA) was successfully doped on the POP (code-named nTPB, with 1,3,5-triphenylbenzene as the monomer) by grafting mode and impregnation, respectively. The effects of different doping modes on the textural properties and the CO₂ adsorption performance of nTPB were studied. It was found that both the surface area and pore volume of nTPB decreased after EDA doping. With the same doping amount of EDA, the pore structure of nTPB was more blocked by impregnation than that of grafting mode. The CO₂ adsorption selectivity of nTPB can be significantly improved by the two doping modes, but only grafting mode can promote the CO₂ adsorption capacity (from 4.4 mmol/g to 5.2 mmol/g at 0℃ and 10⁵ Pa) of nTPB, and that of nTPB doped with impregnation was only 3.4 mmol/g at 0℃ and 10⁵ Pa, due to the pores blocked and EDA buried therein. In addition, the ethylene diamine-doped nTPB grafted showed the same good reusability as the nTPB matrix.