NH2-functionalized porous aromatic polymers for energy and environmental applications: CO2 capture and clean catalytic Ullmann coupling of aryl chlorides in water

초록

Two carbonyl-based porous aromatic polymers (CBAP-1 and CBAP-2) were synthesized via a Friedel-Crafts benzoylation reaction in the presence of anhydrous AlCl3 catalyst, and post-synthetically functionalized with ethylenediamine (EDA): (CBAP-1(EDA) and CBAP-2(EDA)). A series of microporous carbon materials were also prepared by carbonization of CBAP-1 or CBAP-1(EDA). After their characterization, these materials were tested 1) for CO2 and CH4 adsorption at ambient conditions and 2) as a catalyst for green organic synthesis. The microporous carbon materials exhibited high adsorption capacities for CO2 (216.0-231.6 mg g-1) and CH4 (36.6-38.1 mg g-1), whereas high CO2/N2 (97.2 and 87.8) and CO2/CH4 (24.3 and 22.3) selectivities were observed with CBAP-1(EDA) and CBAP-2(EDA) at 273 K/1 bar. Pd NPs immobilized on CBAP-1(EDA) was prepared and tested as a solid catalyst for environmentally-benign Ullmann self-coupling of aryl chlorides in water medium, which showed excellent catalytic performance with a series of aryl chlorides. The catalyst was recovered easily by simple filtration and could be reused six times without loss of its initial activity. The high stability of the catalyst was confirmed by hot filtration and ICP analysis. This work demonstrated an easy synthesis and subsequent post-synthesis organic functionalization of advanced porous polymers for the first time, which may open a new avenue for a broad range of industrial applications.