源自密胺基多孔聚合物的富氮微孔炭及选择性吸附CO_2

以间苯二甲醛和三聚氰胺为原料,通过Schiff碱缩合反应合成了密胺基多孔聚合物(POP),经高温炭化后得到富氮微孔炭(NMC).利用N2吸脱附和傅里叶变换红外(FTIR)光谱表征了POP和炭化后产物NMC的结构和组成,与POP相比,NMC的官能团数量减少,比表面积和微孔孔容大幅增加.元素分析表明NMC含氮量高达12.5%(w).采用体积法测定了CO2、CH4和N2在NMC上的单组分吸附平衡等温线,NMC展示出良好的CO2吸附性能,298 K、100 kPa下CO2平衡吸附量可达2.34 mmol·g-1.双位Langmuir(DSL)模型和单位Langmuir(SSL)模型分别较好地描述了CO2、CH4和N2在NMC上的吸附平衡数据,在此基础上,应用理想吸附溶液理论(IAST)预测了双组分混合气在NMC上的吸附等温线,结果表明NMC对CO2-N2和CO2-CH4有非常高的CO2吸附选择性,分别为144.9和12.8.

Nitrogen-Rich Microporous Carbon Derived from Melamine-Based Porous Polymer for Selective CO2 Adsorption

Nitrogen-rich microporous carbon (NMC) was prepared by the carbonization of a melaminebased porous polymer (POP), which was synthesized via a Schiff base condensation using isophthalaldehyde and melamine as starting materials. N₂ adsorption-desorption and Fourier transform infrared (FTIR) spectroscopy were used to characterize the structural properties of POP and the derived NMC. NMC contains less functional groups and has a higher specific surface area and microporous volume compared to POP. NMC has a N content of up to 12.5% (w), as determined by elemental analysis. Single-component adsorption equilibrium isotherms of CO₂, CH₄, and N₂ on NMC were obtained using a volumetric method. NMC has a good CO₂ capture property and its CO₂ adsorption capacity was 2.34 mmol·g^-1 at 298 K and 100 kPa. Dual-site Langmuir (DSL) or single-site Langmuir (SSL) models appropriately describe the adsorption equilibrium behavior of CO₂, CH₄, and N₂ on NMC. Based on the combined fitting parameters, binary adsorption isotherms were predicted by ideal adsorbed solution theory (IAST). Very high adsorption selectivities of CO₂ over N₂ and CH₄ were obtained and the values were 144.9 and 12.8, respectively.