Department of Chemistry, University of South Florida , 4202 E. Fowler Avenue, Tampa, Florida 33620, United States.
J Am Chem Soc. 2014 Jun 18;136(24):8654-60. doi: 10.1021/ja502119z. Epub 2014 Jun 5.
In this work, we demonstrate for the first time the introduction of π-complexation into a porous aromatic framework (PAF), affording significant increase in ethylene uptake capacity, as illustrated in the context of Ag(I) ion functionalized PAF-1, PAF-1-SO3Ag. IAST calculations using single-component-isotherm data and an equimolar ethylene/ethane ratio at 296 K reveal that PAF-1-SO3Ag shows exceptionally high ethylene/ethane adsorption selectivity (Sads: 27 to 125), far surpassing benchmark zeolite and any other MOF reported in literature. The formation of π-complexation between ethylene molecules and Ag(I) ions in PAF-1-SO3Ag has been evidenced by the high isosteric heats of adsorption of C2H4 and also proved by in situ IR spectroscopy studies. Transient breakthrough experiments, supported by simulations, indicate the feasibility of PAF-1-SO3Ag for producing 99.95%+ pure C2H4 in a Pressure Swing Adsorption operation. Our work herein thus suggests a new perspective to functionalizing PAFs and other types of advanced porous materials for highly selective adsorption of ethylene over ethane.
在这项工作中，我们首次展示了将π-络合作用引入多孔芳香骨架（PAF）中，从而显著提高了乙烯的吸收能力，如图中 Ag(I) 离子功能化 PAF-1、PAF-1-SO3Ag 的情况所示。使用单组分吸附等温线数据和 296 K 下等摩尔乙烯/乙烷比的 IAST 计算表明，PAF-1-SO3Ag 表现出异常高的乙烯/乙烷吸附选择性（Sads：27 至 125），远远超过基准沸石和文献中报道的任何其他 MOF。PAF-1-SO3Ag 中乙烯分子和 Ag(I) 离子之间形成 π-络合作用，这一点可以通过 C2H4 的高等吸附热得到证明，原位红外光谱研究也证明了这一点。在模拟的支持下，瞬态穿透实验表明 PAF-1-SO3Ag 在变压吸附操作中生产 99.95%+纯乙烯的可行性。因此，我们的工作为功能化 PAF 及其他类型的先进多孔材料提供了一个新的视角，以实现对乙烯相对于乙烷的高选择性吸附。
