Structure Regulation of MOF Nanosheet Membrane for Accurate H 2 /CO 2 Separation.

High-purity H 2 production accompanied with a precise decarbonization opens an avenue to approach a carbon-neutral society. Metal-organic framework nanosheet membranes provide great opportunities for an accurate and fast H 2 /CO 2 separation, CO 2 leakage through the membrane interlayer galleries decided the ultimate separation accuracy. Here we introduce low dose amino side groups into the Zn 2 (benzimidazolate) 4 conformation. Physisorbed CO 2 served as interlayer linkers, gently regulated and stabilized the interlayer spacing. These evoked a synergistic effect of CO 2 adsorption-assisted molecular sieving and steric hinderance, whilst exquisitely preserving apertures for high-speed H 2 transport. The optimized amino membranes set a new record for ultrathin nanosheet membranes in H 2 /CO 2 separation (mixture separation factor: 1158, H 2 permeance: 1417 gas permeation unit). This strategy provides an effective way to customize ultrathin nanosheet membranes with desirable molecular sieving ability.