Selectivity enhancement by the presence of grain boundary in chabazite zeolite membranes investigated by non-equilibrium molecular dynamics

The effects of a sub-nanometer grain boundary in all-silica chabazite (CHA) zeolite membranes on their permeation properties were investigated by non-equilibrium molecular dynamics (NEMD). results indicated that at the total pressure 0.5 MPa, 298 K, CO2 selectivity toward CH4 drastically increased due to presence region inside membrane. This was consequence selective condensation boundary. calculated for perfect crystal CHA range 183–278 and depended surface orientation modeled membranes. Notably, comparable previously reported values. Two different membrane structures containing approximately 0.6 nm using NEMD. In case located membrane, condensed molecules prevented CH4, resulting significantly selectivity. NEMD suggest compared membranes, increases performance, selectivity, permeability.