电化学法合成金属有机骨架化合物对含氧挥发性有机物的吸附性能

Adsorption properties of MOFs by electrochemical synthesis for oxygenated VOCs

使用电化学法合成了3种金属有机骨架化合物(MOFs)Cu-BTC、MIL-100(Al)、ZIF-8,测定了3种MOFs对代表性含氧挥发性有机物(VOCs)异丙醇与乙酸乙酯的平衡吸附容量,并结合不同湿度条件下的穿透实验,考察了MOFs对于含氧VOCs的吸附性能。结果表明,ZIF-8对异丙醇和乙酸乙酯的平衡吸附容量最大,通过Langmuir模型拟合所得的异丙醇和乙酸乙酯理论最大吸附容量分别达到了530、613mg/g。在穿透实验中,总体上看,ZIF-8对异丙醇、乙酸乙酯的吸附容量利用率也最大,达到90.9%和87.8%。而随着湿度增加,3种MOFs的吸附容量利用率均下降。相比Cu-BTC和MIL-100(Al),ZIF-8在高湿度条件下能保持最佳的吸附性能。当相对湿度从3%±2%增加到90%±2%后,其对异丙醇、乙酸乙酯的穿透吸附量仅下降10.9%和22.7%。3种MOFs重复使用4次后仍能保持较好的吸附性能。

Three metal organic frameworks(MOFs)including Cu-BTC,MIL-100(Al)and ZIF-8 were synthesized by the electrochemical method.The equilibrium adsorption capacities of three MOFs for the selected oxygenated volatile organic compounds(VOCs)including isopropanol and ethyl acetate were determined,and the adsorption breakthrough experiments of isopropanol and ethyl acetate under the different humidity conditions were also conducted to investigate the equilibrium adsorption capacities of MOFs for these oxygenated VOCs.The results showed that ZIF-8 had the largest equilibrium adsorption capacity for isopropanol and ethyl acetate,with theoretical maximum adsorption capacities calculated by Langmuir model of 530 and 613 mg/g for isopropanol and ethyl acetate,respectively.The result of breakthrough experiment showed that the adsorption capacity utilization rate of ZIF-8 for isopropanol and ethyl acetate was also the highest generally among the three MOFs,reaching 90.9% and 87.8%,respectively.With the increase of humidity,the adsorption capacity utilization rate of three MOFs all decreased.Compared with Cu-BTC and MIL-100(Al),ZIF-8 remained the best adsorption ability under high humidity.When humidity increased from 3%±2% to 90%±2%,the adsorption capacity of ZIF-8 for isopropanol and ethyl acetate only decreased by 10.9%and 22.7%,respectively.The adsorption performance of regenerated MOFs maintained well after reused for four times.