Synthesis, Structure, Assembly, and Modulation of the CO2 Adsorption Properties of a Zinc-Adeninate Macrocycle

A bio-metal-organic framework for highly selective CO(2) capture: A molecular simulation study

A recently synthesized bio-metal-organic framework (bio-MOF-11) is investigated for CO(2) capture by molecular simulation. The adenine biomolecular linkers in bio-MOF-11 contain Lewis basic amino and pyrimidine groups as the preferential adsorption sites. The simulated and experimental adsorption isotherms of pure CO(2), H(2), and N(2) are in perfect agreement. Bio-MOF-11 exhibits larger adsorption capacities compared to numerous zeolites, activated carbons, and MOFs, which is attributed to the presence of multiple Lewis basic sites and nano-sized channels. The results for the adsorption of CO(2)/H(2) and CO(2)/N(2) mixtures in bio-MOF-11 show that CO(2) is more dominantly adsorbed than H(2) and N(2). With increasing pressure, the selectivity of CO(2)/H(2) initially increases owing to the strong interactions between CO(2) and the framework, and then decreases as a consequence of the entropy effect. However, the selectivity of CO(2)/N(2) monotonically increases with increasing pressure and finally reaches a constant. The selectivities in bio-MOF-11 are higher than in many nanoporous materials. The simulation results also reveal that a small amount of H(2)O has a negligible effect on the separation of CO(2)/H(2) and CO(2)/N(2) mixtures. The simulation study provides quantitative microscopic insight into the adsorption mechanism in bio-MOF-11 and suggests that bio-MOF-11 may be interesting for pre- and post-combustion CO(2) capture.

Can metal-organic framework materials play a useful role in large-scale carbon dioxide separations?

Metal-organic frameworks (MOFs) are a fascinating class of crystalline nanoporous materials that can be synthesized with a diverse range of pore dimensions, topologies, and chemical functionality. As with other well-known nanoporous materials, such as activated carbon and zeolites, MOFs have potential uses in a range of chemical separation applications because of the possibility of selective adsorption and diffusion of molecules in their pores. We review the current state of knowledge surrounding the possibility of using MOFs in large-scale carbon dioxide separations. There are reasons to be optimistic that MOFs may make useful contributions to this important problem, but there are several critical issues for which only very limited information is available. By identifying these issues, we provide what we hope is a path forward to definitively answering the question posed in our title.