Metal-Organic Framework (MOF)-based Adsorbents for Gas Separations in the Petrochemicals Industry

从二氮（N2）中轻松分离一氧化碳（CO）有机会从烟道气中提供新的CO供应。一氧化碳是一种重要的资源，因为它在化学工业中被用作甲醇和其他碳氢化合物的原料。目前的CO/N2分离涉及能量密集的低温分离，这对于烟道气的使用是不切实际的。另一种替代技术，金属有机框架（mof），在分离许多常见气体（如H22， CO23, N24, CH43，水蒸气）以及更奇特的有毒气体（如沙林5,6）方面显示出了希望。人们对CO/N2的分离表现出了一些兴趣，但这项研究已被替代大气气体所掩盖。由于相似的化学特性，如沸点和物理尺寸，从N2中分离CO已被证明是困难的。相反，我们可以利用CO通过n-反键轨道与金属中心反键的倾向。这导致了一个合乎逻辑的结论，即一个成功的MOF从N2中分离CO将取决于MOF的金属中心和气体吸附可达的金属位的数量。密度泛函理论（DFT）计算表明，许多金属对CO7,8的吸附感兴趣，而许多方法已被证明可以在MOF9,10,11的结构中创建额外的可访问金属位点。最近，在mof中掺杂活性更强的金属离子，显示出CO选择性的增加。以这些思想为基础，我们希望通过选择性吸附和解吸CO，开发出适合于CO与N2分离的mof，以提供高纯度的资源。

Facile separation of Carbon Monoxide (CO) from Dinitrogen (N2) has the opportunity to provide a new supply of CO from flue gases. CO is an important resource due to its use within chemical industry as a stock fed for methanol and other hydrocarbons. Current CO/N2 separation involves energy intense cryogenic separation which is impractical for the flue gas use1. An alternative technique, metal organic frameworks (MOFs), has shown promise in the separation of a number of common gases such as H22, CO23, N24, CH43, water vapour, as well as more exotic toxic gases such as sarin5,6. Some interest has been shown in the separation of CO/N2 however this research has been eclipsed by alternative atmospheric gases. Separation of CO from N2 has been shown to be difficult due to similar chemical characteristics such as boiling point and physical size. Instead we can take advantage of CO's propensity to backbond with metal centres via n-antibonding orbitals. This leads to a logical conclusion that a successful MOF for the separation of CO from N2 will be dependent on the metal centre of the MOF and the amount of accessible metal sites for gas adsorption. Density functional theory (DFT) calculations have shown that a number of metals are of interest for the adsorption of CO7,8 whilst a number of approaches have been shown to create additional accessible metal sites within the structure of the MOF9,10,11. More recently the doping of MOFs with more reactive metal ions has shown increases in the CO selectivity12. Using these ideas as a foundation, we hope to develop a selection of MOFs suitable for the separation of CO from N2 by selectively adsorbing and desorbing CO to provide a high purity resource.