Design of metal-organic frameworks for selective adsorption of benzene from vinyl acetate

Vinyl acetate is an important organic chemical raw material, which can be used to synthesize a variety of polymer products. However, vinyl acetate products synthesized by the acetylene method contain about 100 ppm benzene impurities, which seriously restricts the synthesis of downstream high-end products. In this work, we screen and design high performance MOF materials for the separation of trace benzene in vinyl acetate using molecular simulation method. Based on the properties of benzene, 152 MOFs are selected from CoRE MOF database for high-throughput calculation. It is revealed that the MOFs with unsaturated metal sites and electron-withdrawing groups on organic ligands are favorable for the adsorption of benzene molecules. 5 top-performing MOFs selected are ECOLEP, FUTDII, EYOQAL, DUFGOB and FEWTUY. We modify ECOLEP, which has the highest adsorption selectivity for benzene, to design a series of MOFs to obtain better adsorbents. Four ECOLEPM (M = Ni, Cu, Zn, Mg) materials are designed by changing the type of the metal sites, and ECOLEP-Cu performs best with the selectivity of 180300.2. Furthermore, in order to determine the effect of organic ligands, -CF3 group is introduced into ECOLEP-Cu. Finally, ECOLEP-Cu is selected as the most promising material for the removal of trace benzene from vinyl acetate.