一维超微孔MOFsM3(HCOO)6(M=Fe,Co,Ni)用于乙烯-丙烯混合物的分离

摘要

Olefins are important industrial chemicals,but the energy consumption in their production is very large.In this work,[M3(HCOO)6] (M=Fe,Co,Ni) were synthesized using solvothermal method and characterized by XRD,N2-sorption,SEM.We studied the pore structure effect on their ethylene and propylene adsorption properties.In a fixed-bed gas separation apparatus,ethylene/propylene separation abilities of [M3(HCOO)6] series were studied under dynamic conditions.The results showed that the pore sizes in MOFs can be rationally tuned through metal substitution.Larger pore sizes will lead to higher ethylene and propylene adsorption capacities,but lower propylene/ethylene adsorption selectivity and separation efficiency.Smaller pore sizes will increase the propylene adsorption,thus improve their propylene/ethylene adsorption selectivity and separation ability.In this work,we show that metal substitution on [M3(HCOO)6] series can effectively increase the propylene/ethylene separation ability,and this strategy provides an idea for efficient separation of light hydrocarbons.%烯烃是重要的化工原料,其生产过程中存在分离提纯能耗过大的问题.本文通过溶剂热方法合成了超微孔[M3(HCOO)6] (M=Fe,Co,Ni)系列材料,利用XRD、N2吸附、SEM等对其结构与形貌进行了袁征,详细考察了[M3(HCOO)6]的不同孔道结构对于乙烯和丙烯吸附的影响.结合固定床气体分离装置,测试了[M3(HCOO)6]对于乙烯-丙烯气体混合物的动力学分离性能.结果表明:通过构建不同的中心金属,有效地控制了MOFs的孔径尺寸;较大的孔径尺寸会提高乙烯和丙烯的吸附量,但对丙烯/乙烯的吸附选择性不高,分离性能较低;较小的孔径有利于提高对丙烯的吸附强度,从而提高丙烯/乙烯的吸附选择性与分离性能.本文通过对[M3(HCOO)6]系列MOFs不同中心金属的替换,提高了其对于丙烯/乙烯混合物的分离性能,为实现低碳烃混合物的高效分离提供了思路.