低成本季铵盐类多孔材料的合成及氨气吸附性能

Synthesis of Low-cost Quaternary Ammonium Porous Materials and Their Ammonia Adsorption Performance

氨气是雾霾的主要污染源之一,开发高效的氨气吸附材料是一种有效的防治方法.本文选用4,4′-联吡啶、α,α′-二溴-对二甲苯和1,2,4,5-四(溴甲基)苯作为构筑单元,利用无需催化剂且操作简便的季铵化反应,原位合成了具有路易斯酸活性位点的多孔材料PAF-C1和PAF-C2.得益于骨架中路易斯酸位点的存在,这两种材料均具有良好的氨气吸附性能.其中,PAF-C2骨架中含有更多的路易斯酸位点,因此具备更优异的氨气吸附性能,在298 K和1×10^(5)Pa条件下其氨气吸附量可达5.5 mmol/g.此外,探究了材料的合成条件(温度、溶剂和保护气体)、原料用量及合成方式的影响.结果表明,以上不同反应条件制备的材料均保持优良的氨气吸附性能,从而使实现工业化合成高效氨气吸附材料成为可能.

Ammonia(NH3)is a primary source of haze pollution,and developing NH3 adsorbent materials with high-efficiency is an effective way to address this problem.In this work,4,4′-dipyridyl,α,α′-dibromo-p-xylene and 1,2,4,5-tetrakis(bromomethyl)benzene were selected as the building units,via a catalyst-free and mild in situ quaternarization reaction,resulting in PAF-C1 and PAF-C2 with abundant Lewis acid active sites synthesized.Benefiting from the presence of Lewis acid active sites in the skeleton,both PAF-C1 and PAF-C2 exhibited excellent NH3 adsorption performance.Compared to PAF-C1,PAF-C2 possessed more Lewis acid sites,thus exhibited superior adsorption capacity with an NH3 adsorption capacity of 5.5 mmol/g at 298 K and 1×10^(5)Pa.Additionally,the synthetic conditions(including temperature,solvent and gas atmosphere),the amounts of monomers and synthetic methods were explored,respectively.The results showed that all the materials obtained under different reaction conditions maintained good NH3 adsorption activities,suggesting the potential for industrial-scale production of highly efficient NH3 adsorption materials.