高通量计算筛选分离乙烷/乙烯的金属有机框架材料

High-Throughput Computational Screening for Metal-Organic Frameworks on the Separation of Ethane/Ethylene

乙烯属于具有高附加值的化工产品之一,从乙烷蒸汽裂解产生乙烯后的混合气体中分离乙烯具有重要的应用,筛选用于C_(2)H_(6)/C_(2)H_(4)吸附分离的高性能金属有机骨架(MOF)材料迫在眉睫.通过先前文献报道从CoRE MOFs(2019)数据库中得出的重要结构吸附性质关系(SAPR),随后用于在G-MOFs和hMOFs数据库中筛选高性能MOFs.综合考虑热稳定性和吸附剂性能评分(APS),筛选出6种有希望用于C_(2)H_(6)/C_(2)H_(4)分离的MOFs,其中C_2H_6吸附量均大于1.05 mmol/g,选择性均大于1.99,其性能优于大多数文献报道的框架.研究发现这些MOFs对C_2H_6,C_2H_4的吸附等温线属于I型曲线,C_(2)H_(6)/C_(2)H_(4)分离的机理为热力学分离.此外,通过能量分解分析(EDA)的独立梯度模型(IGMH)电子结构计算,发现客体与框架之间的相互作用为vdW作用.当前采用的基于SAPR筛选方法有助于快速预测分离新型MOF吸附剂.

Ethylene is one of the chemical products with high value.The separation of ethylene from the mixed gas produced by ethane steam cracking has important applications.It is urgent to screen for high-performance metal organic framework(MOF)materials for the adsorption separation of C_(2)H_(6)/C_(2)H_(4) The important structural adsorption property relationship(SAPR)obtained from the CoRE MOFs(2019)database through previous reports was subsequently used to screen for high-performance MOFs in G-MOFs and hMOFs databases.Taking into account both thermal stability and adsorbent performance score(APS),six MOFs with potential for C_(2)H_(6)/C_(2)H_(4) separation were selected.Among them,the adsorption capacity of CH.is larger than 1.05 mmol/g,with the selectivity larger than 1.99.Note that their performances are superior to most frameworks reported in literature.Research has found that the adsorption isotherms of these MOFs on CH_(6) and C_(2)H_(4) belong to type I curves,and the separation mechanism of C_(2)H_(6)/C_(2)H_(4) is thermodynamic separation.In addition,through the independent gradient model(IGMH)electronic structure calculation of energy decomposition analysis(EDA),it is found that the interactions between the adsorbate and the framework are vdW interaction.The current SAPR based screening method helps to quickly predict novel MOF adsorbents.