Development of Diamine-Appended Metal-Organic Frameworks as Adsorbents for Submarine Life Support Systems

The proposed work will focus on the development and optimization of a recently discovered class of amine-grafted metal-organic frameworks for improved, efficient, and robust carbon dioxide (CO2) capture in Navy submarines. Metal-organic frameworks (MOFs) are 3-dimensional coordination solids composed of metal cations and organic linkers and, due to their substantial porosity and tunability, are of great interest for a wide range of gas adsorption application such as CO2 capture. Our recent work led to the development of a new class of MOFs with dangling amines grafted onto framework open metal sites that exhibit high-capacity, highly selective, cooperative adsorption of CO2 and enable far lower recycling temperatures and regeneration energies than currently accessible with conventional aqueous amine solutions. The initial development of these materials will involve optimization of synthetic variants and eventual pellet/granule processing with the goal of identifying and producing the best materials to meet the Navy criteria for achieving an on-board background CO2 level of 0.5% (or less), maximal space and volume savings, and long-term stability to humidity and recycling.