Exceptional high selectivity of hydrogen/methane separation on a phosphonate-based MOF membrane with exclusion of methane molecules.

A phosphonate-based metal-organic framework membrane was constructed on a porous anodic alumina membrane (PAAM) substrate for H2/CH4 separation for the first time. Owing to the ultra-micro pore windows, this membrane exhibited effective size exclusion for CH4 molecules but suitable permeance for H2 molecules, giving rise to an exceptional high H2/CH4 separation selectivity.