Coskun Research Group has recently published a new article in the journal Chem, entitled "Ultrahigh permeance metal coated porous graphene membranes with tunable gas selectivities"
Membranes play an important role in gas separation on account of their low cost, energy efficiency, and durability. Gas-separation membranes, however, are subject to permeability-selectivity trade-off, i.e., atomically thin 2D materials such as porous graphene can provide ultrahigh permeances in the range of ∼105–107 GPU but suffer from low gas selectivity. Here, we show a new concept to enhance the selectivity of graphene-based membranes by employing adsorptive separation for binary gas mixtures. The deposition of “microislands” of Pd and Ni on the porous double-layer graphene support allowed us to selectively target H2 in He/H2 and CO2 in H2/CO2 mixtures, respectively, thus enabling efficient separation of He and also leading to the highest H2/CO2 separation factor of 26 within the ∼105 GPU permeance range. Moreover, the selective targeting of individual gases in a membrane setting through adsorptive separation at room temperature can be a promising alternative for economical gas separation.