(665d) Molecular Modeling of the Adsorption of Harmful Gases in Metal-Organic Frameworks

Metal-organic frameworks (MOFs) are a new class of nanoporous materials that have potential applications in separation processes, catalysis, energy storage and sensing. MOFs are inorganic-organic hybrids that are synthesized using organic linker molecules and metal joints that self-assemble to form materials with well-defined pores, high surface areas, and tunable chemical functionalities. By judiciously choosing the metal cluster and organic linker, MOFs can be designed such that the materials have desired magnetic, optical, catalytic, or selective adsorption properties.

MOFs with anionic frameworks are of particular interest for sensing applications. [1] These negatively charged frameworks are balanced by extraframework cations; therefore, they are also called Zeolite-like MOFs (ZMOFs). The combination of various extraframework cations and the versatility of functionalizing organic linkers makes ZMOFs promising candidates for use as chemical sensors of harmful gases.

Molecular modeling methods including grand canonical Monte Carlo (GCMC) and molecular dynamics (MD) simulations have been used to investigate the adsorption capabilities of ZMOFs for harmful gases such as ammonia, NOx, SO2, CO, etc. ZMOFs with different topologies and cations were considered. Their performance under humidity has also been evaluated. Results including adsorption isotherms, heats of adsorption and diffusivities will be presented.

[1] Liu, Y., Kravtsov, V. Ch., Larsen, R., Eddaoudi, M. ?Molecular building blocks approach to the assembly of zeolite-like metal-organic frameworks (ZMOFs) with extra-large cavities?, Chem. Comm., 2006, 1488-1490.