Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX, 76019, USA.
Department of Chemical and Process Engineering, University of Canterbury, Christchurch, 8140, New Zealand.
Angew Chem Int Ed Engl. 2020 Nov 16;59(47):21001-21006. doi: 10.1002/anie.202010405. Epub 2020 Sep 30.
Purifying alkenes from alkanes requires cryogenic distillation. This consumes energy equivalent to countries of ca. 5 million people. Replacing distillation with adsorption processes would significantly increase energy efficiency. Trade-offs between kinetics, selectivity, capacity, and heat of adsorption have prevented production of an optimal adsorbent. We report adsorbents that overcome these trade-offs. [Cu-Br] and [Cu-H] are air-stable trinuclear complexes that undergo reversible solid-state inter-molecular rearrangements to produce dinuclear [Cu-Br⋅(alkene)] and [Cu-H⋅(alkene)] . The reversible solid-state rearrangement, confirmed in situ using powder X-ray diffraction, allows adsorbent design trade-offs to be overcome, coupling low heat of adsorption (-10 to -17 kJ mol ), high alkene:alkane selectivity (47; 29), and uptake capacity (>2.5 mol mol ). Most remarkably, [Cu-H] displays fast uptake and regenerates capacity within 10 minutes.
从烷烃中纯化烯烃需要低温蒸馏。这消耗的能量相当于大约 500 万人的国家的能源消耗。用吸附工艺取代蒸馏将显著提高能源效率。动力学、选择性、容量和吸附热之间的权衡阻碍了最佳吸附剂的生产。我们报告了克服这些权衡的吸附剂。[Cu-Br]和[Cu-H]是空气稳定的三核配合物，它们经历可逆的固态分子间重排，生成二核[Cu-Br⋅(烯烃)]和[Cu-H⋅(烯烃)]。使用粉末 X 射线衍射原位确认的可逆固态重排允许克服吸附剂设计的权衡，结合低的吸附热（-10 至-17 kJ mol）、高的烯烃：烷烃选择性（47；29）和吸附容量（>2.5 mol mol）。最显著的是，[Cu-H]显示出快速的吸附和解吸能力，在 10 分钟内即可再生。
