Center for Reticular Chemistry at the California NanoSystems Institute, Department of Chemistry and Biochemistry, University of California, 607 Charles E. Young Drive East, Los Angeles, CA 90095, USA.
Proc Natl Acad Sci U S A. 2009 Dec 8;106(49):20637-40. doi: 10.1073/pnas.0909718106. Epub 2009 Nov 30.
Selective capture of CO(2), which is essential for natural gas purification and CO(2) sequestration, has been reported in zeolites, porous membranes, and amine solutions. However, all such systems require substantial energy input for release of captured CO(2), leading to low energy efficiency and high cost. A new class of materials named metal-organic frameworks (MOFs) has also been demonstrated to take up voluminous amounts of CO(2). However, these studies have been largely limited to equilibrium uptake measurements, which are a poor predictor of separation ability, rather than the more industrially relevant kinetic (dynamic) capacity. Here, we report that a known MOF, Mg-MOF-74, with open magnesium sites, rivals competitive materials in CO(2) capture, with 8.9 wt. % dynamic capacity, and undergoes facile CO(2) release at significantly lower temperature, 80 degrees C. Mg-MOF-74 offers an excellent balance between dynamic capacity and regeneration. These results demonstrate the potential of MOFs with open metal sites as efficient CO(2) capture media.
已报道沸石、多孔膜和胺溶液等材料中存在 CO2 的选择性捕集，这对天然气的净化和 CO2 的封存至关重要。然而，所有这些系统在释放捕获的 CO2 时都需要大量的能量输入，导致能量效率低、成本高。一类名为金属有机骨架（MOF）的新型材料也被证明可以吸收大量的 CO2。然而，这些研究在很大程度上仅限于平衡吸收测量，这对于分离能力是一个很差的预测指标，而不是更具工业相关性的动力学（动态）容量。在这里，我们报告说，具有开放镁位的已知 MOF，Mg-MOF-74，在 CO2 捕获方面可与竞争性材料相媲美，具有 8.9wt%的动态容量，并且在明显更低的温度 80°C 下可轻松释放 CO2。Mg-MOF-74 在动态容量和再生之间具有极好的平衡。这些结果表明具有开放金属位的 MOFs 作为高效 CO2 捕获介质具有潜力。
