Graphene-like Poly(triazine imide) as N₂-Selective Ultrathin Membrane for Postcombustion CO₂ Capture

To reduce the emission of greenhouse gases, the separation of CO 2 from flue gases emitted by power plants with combustion of carbon-based fossil fuels is of great importance. Compared with CO 2 -selective membranes, N 2 -selective membranes are more promising for such systems with low concentrations of CO 2 . Using density functional theory (DFT) calculations and molecular dynamic (MD) simulations, we demonstrated in this work that the poly(triazine imide) (PTI) membrane can be efficiently employed to separate N 2 from CO 2 with a selectivity of 273 and a N 2 permeance of 10 6 GPU, superior to those of most conventional membranes. Furthermore, it was revealed that the presence of H 2 O has a negligible influence on gas separation performance of the PTI membrane. This experimentally available N 2 -selective ultrathin membrane may be expected to find practical applications in postcombustion CO 2 capture.