A novel boron nitrogen monolayer named as inorganic graphenylene (IGP) was proposed for H-2 purification, and its stability was confirmed by the calculated cohesive energy and phonon dispersion spectrum. Using the density function theory (DFT) calculations and molecular dynamic (MD) simulations, we found that the IGP membrane can fulfill the requirements of both the high H-2 permeance (similar to 10(-3) mol/m(2) s Pa) and high H-2 selectivities (> 10(7)) over H2O, CO2, N-2, CO, and CH4 at 300 K. Excitingly, the MD results matched well with the DFT calculations including the selectivity, permeance as well as the adsorption properties of different gases.