The separation and purification of light olefins is essential to obtain valuable materials from petrochemical feedstock.1 The high energetic cost of cryogenic distillation drives the research for alternative methods of extraction. Transition metals that reversibly complex olefins are being studied to improve the energetic efficiency, but have several problems such as poisoning and deactivation. Homogeneous catalysts present practical issues, such as separation or use of solvents, which are reduced by using related heterogeneous catalysts. In this work, we evaluate a 2D material recently synthesized by Kambe et al.,2 with benzenehexathiol and Ni atoms in a 2:3 ratio, which was recently reported to coordinate ethylene.3 In this presentation, we extend our previous computational work in molecular complexes4-6 to the 2D system, using periodic boundary conditions (PBC) with a screened-hybrid DFT functional.7 In addition to those previously proposed, we include binding motifs both from the molecular analogues (e.g. coordination along the S-Ni bond) and those arising from the periodicity (e.g. coordination between different Ni atoms). Relative energies of the coordination products and their formation pathways are compared to find the preferred mechanism. Different alkene coverage levels on the surface are used to evaluate the molecular efficiency of the material. Reaction barriers and energies are similar to those obtained for molecular systems. Coordination is favored up to one ethylene per nickel atom. The extended material eases practical issues and weight efficiency improves. In conclusion, we believe that it is a promising candidate for an olefin purification catalyst. References: 1 Eldridge, R.B. Ind. Eng. Chem. Res. 1993, 32, 2208-2212. 2 Kambe, T.; Sakamoto, R.; Hoshiko, K.; Takada, K.; Miyachi, M.; Ryu, J.H.; Sasaki, S.; Kim, J.; Nakazato, J.; Takata, M.; Nishihara, H. J. Am. Chem. Soc. 2013, 135, 2462-2465. 3 Tang, Q.; Zhou, Z. Electronic J. Phys. Chem. C 2013, 117, 14125-14129. 4 Dang, L.; Shibl, M.F.; Yang, X.; Alak, A.; Harrison, D.J.; Fekl, U.; Brothers, E.N.; Hall, M.B. J. Am. Chem. Soc. 2012, 134, 4481-4484. 5 Dang, L.; Shibl, M.F.; Yang, X.; Harrison, D.J.; Alak, A.; Lough, A.J.; Fekl, U.; Brothers, E.N.; Hall, M.B. Inorg.Chem. 2013, 52, 3711–3723 6 Li, H.; Brothers, E.N.; Hall, M.B. Inorg. Chem. 2014, 53, 9679–96915 7 Moncho, S.; Brothers, E.N.; Hall, M.B. J. Mol. Model. 2015 In press

DFT study on a 2D, π-conjugated, nickel metallo-organic framework for ethylene purification

250th National Meeting (2015)

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