High efficiency hydrogen purification through P₂C₃ membrane: A theoretical study

It is critical to design an effective two-dimensional membrane for hydrogen purification from the mixed gas, due to its wide range of scientific and industrial applications. In this work, we investigate the hydrogen separation performance of P₂C₃ membranes by density functional theory and molecular dynamics simulations. The results show that the energy barrier of the H₂ molecule through the P₂C₃ film is only 0.18 eV, while the energy barriers of the CO, N₂, CO₂, and CH₄ molecules are 0.77 eV, 0.87 eV, 0.52 eV, and 1.75 eV, respectively. In addition, the P₂C₃ film has high H₂ selectivity toward other gas molecules and high H₂ permeability at room temperature. Under 6% tensile strain, 82% hydrogen molecules pass through the film with a H₂ permeance of 2.22 × 10⁷ gas permeance unit (GPU), while other molecules cannot across the membrane at all. Therefore, the P₂C₃ membrane is an excellent material for hydrogen purification. (paper)