Selective adsorption of liquid long-chainα-olefin/paraffin on Mg-MOF-74:Adsorption behavior and interaction mechanism  

作　　者：Ruihan Yang Shafqat Ullah Xiao Chen Junxiang Ma Yuan Gao Yujun Wang Guangsheng Luo 

机构地区：[1]State Key Lab of Chemical Engineering,Department of Chemical Engineering,Tsinghua University,Beijing 100084,China [2]Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology,Department of Chemical Engineering,Tsinghua University,Beijing 100084,China [3]Lu’an Chemical Group Co.,Ltd.,Changzhi 046299,China

出　　处：《Nano Research》2023年第1期1595-1605,共11页纳米研究（英文版）

基　　金：This work was financially supported by the National Natural Science Foundation of China(Nos.21878169 and 21991102);Key Technologies Research and Development Program of China(No.2019YFA0905100);Tsinghua University Initiative Scientific Research Program(No.2018Z05JZY010).

摘　　要：The liquid products of Fischer–Tropsch synthesis with a high content of linearα-olefins can act as valuable raw materials for increasing high added-valueα-olefin production if the challenging separation of long-chainα-olefin/paraffin is achieved.Adsorption separation is an efficient alternative to energy-intensive distillation.Herein,the selective adsorption behavior and interaction mechanism of liquidα-olefin/paraffin on Mg metal–organic framework(MOF)-74 were investigated using a combination of batch adsorption experiments and molecular simulation techniques.Mg-MOF-74 exhibited 301 and 333 mg/g olefin adsorption capacities for C6 and C8 linearα-olefins in binary olefin/paraffin mixtures,respectively,and was still unsaturated at high olefin concentrations.The adsorption isotherms were analyzed and compared with the simulated results by configurational-bias grand canonical Monte Carlo(CB-GCMC)simulation.The visualized adsorption sites by CB-GCMC simulation indicated that all adsorbates were arranged in hexagonal shapes and preferentially adsorbed by the vertex of the hexagon,where the metal node magnesium is located.The adsorption energies were−1.456 and−0.378 eV for C8 linearα-olefin and paraffin,respectively,calculated by density functional theory simulation based on the visualized adsorption sites.The charge transfer was analyzed,and the contributions of different kinds of interactions to the overall adsorption energy were quantified by principle orbital interaction analysis to further reveal the difference in adsorption energy betweenα-olefin/paraffin and Mg-MOF-74.This work also provides a general means to investigate the liquid adsorption performance and host–guest interactions in the adsorption or catalytic processes of nanoporous materials.

关 键 词：linearα-olefin metal-organic frameworks liquid-phase adsorption molecular simulations principle orbital interaction 

分 类 号：O64[理学—物理化学]