Improved permeability and selectivity in porous graphene for hydrogen purification.

Porous graphene is a promising material for the realization of low-cost, large-area and lightweight gas separation. However, molecular-sieving membranes based on porous materials reported thus far generally cannot fulfill the requirements of both high permeability and high selectivity. Simultaneously meeting the goals of high permeability and high selectivity remains a great challenge. As we demonstrate here, with the development of an inter-layer-connected porous graphene bilayer, both the permeability and selectivity are significantly improved, and a high criterion of selectivity for H2 over CH4 (10(24) at room temperature) as well as a high flux of H2 (2.4 × 10(5) Gas Permeance Unit) has been reached. Our studies highlight a new approach towards the final goal of high-permeability and high-selectivity molecular-sieving membranes using simple structural engineering.