Study and development of new metal-organic frameworks based membranes for separation of multicomponent gas mixtures

This project is focused on development of new metal-organic frameworks (MOFs) based materials for purification/separation of multicomponent gas mixtures. We perform computational modelling in order to design new MOFs membranes for applications of industrial importance including biogas separation and hydrogen adsorption. We develop atomic-scale computational models directly connected to the sorption of gases under realistic conditions and allowing to address its fundamental aspects at the same time. These models are realized in the frame of multi-level workflow, combining both quantum and classical approaches, which provides an opportunity to investigate sorption behaviour of MOFs at a wide range of pressures. While classical force fields cover the normal-pressure region, quantum-level methods are used to study sorption processes under low-pressures, where classical approaches tend to fail quite miserably. We pay significant attention to implementation of the quantum chemical approaches, since MOFs are well-known to be very challenging objects for quantum theory consideration due to the typical big sizes of unit-cell combined with multireference nature of transition metals d-shell. This is reflected in the fact, that routinely used quantum approaches suffer from convergence problems and low computational effectiveness, when applied to MOFs. Therefore, we plan to develop a hybrid quantum chemical model, based on group function concept, allowing effective separation of the system into part, where multireference effects are essential, and environment, allowing single-reference or even force field treatment. Propose methodology will provide an effective and powerful tool for modeling of MOFs with possible applications going beyond sorption properties.