Co-MOF-74的合成及其吸附正己烷/1-己烯性能

Synthesis and the performance of Co-MOF-74 for n-hexane/1-hexene adsorption separation

采用溶剂热方法合成了Co-MOF-74,采用X射线衍射(XRD)、氮气吸附、红外光谱(FTIR)、热重-差热分析(TG-DSC)和扫描电子显微镜(SEM)对其进行表征,研究其吸附正己烷/1-己烯性能。结果表明,优化的Co-MOF-74合成工艺条件为:原料配比n[Co(NO3)2·6H2O]︰n(DHTP)︰n(THF)︰n(H2O)=2︰1︰165︰750,晶化温度100℃,晶化时间24h,150℃活化2h。合成Co-MOF-74对1-己烯和正己烷的静态饱和吸附量分别为125.6mg/g和72.9mg/g,BET比表面积为1209m^2/g,孔体积为0.41cm^3/g,微孔平均孔径为0.66nm。L-F吸附模型能较好地解释Co-MOF-74材料对1-己烯的吸附等温线数据,Co-MOF-74吸附1-己烯的过程是热力学自发放热过程。

Co-MOF-74 was synthesized through solvothermal process.Samples were characterized by using XRD,N2 adsorption,FTIR,TG-DSC and SEM.In addition,the adsorption performances for n-hexane/1-hexene were evaluated.The optimal synthesis conditions were observed as follows:the ratio of raw materials of n[Co(NO3)2·6H2O]:n(DHTP):n(THF):n(H2O)=2:1:165:750,crystallization temperature of 100,crystallization time of 24h,activation temperature℃of 150℃,activation time of 2h.It is indicated that synthesized Co-MOF-74 has static adsorption capacities of 125.6mg/g and 72.9mg/g for 1-hexene and n-hexane,respectively.The BET specific surface area,pore volume and average micropore size are 1209m^2/g,0.41cm^3/g and 0.66nm,respectively.The maximum adsorption amount is determined to be around 130mg/g at adsorption temperature range of 283K to 313K.Furthermore,the adsorption isotherms for 1-hexene on Co-MOF-74 can be explained by using L-F model very well.1-hexene adsorption onto Co-MOF-74 is confirmed to be a spontaneous exothermic process.