Electropolymerization of Molecular‐Sieving Polythiophene Membranes for H2 Separation

Membrane technologies that do not rely on heat for industrial gas separation would lower global energy cost. While polymeric, inorganic, and mixed‐matrix separation membranes have been rapidly developed, the bottleneck is balancing the processability, selectivity, and permeability. Reported here is a softness adjustment of rigid networks (SARs) strategy to produce flexible, stand‐alone, and molecular‐sieving membranes by electropolymerization. Here, 14 membranes were rationally designed and synthesized and their gas separation ability and mechanical performance were studied. The separation performance of the membranes for H2/CO2, H2/N2, and H2/CH4 can exceed the Robeson upper bound, among which, H2/CO2 separation selectivity reaches 50 with 626 Barrer of H2 permeability. The long‐term and chemical stability tests demonstrate their potential for industrial applications. This simple, scalable, and cost‐effective strategy holds promise for the design other polymers for key energy‐intensive separations. Die Weichheit starrer Netzwerke wurde gezielt justiert, um flexible, freistehende Molekularsieb‐Membranen durch Elektropolymerisation herzustellen. Die Membranen erzielen hervorragende H2/CO2‐, H2/N2‐ und H2/CH4‐Trennleistungen und zählen zu besten rein organischen Polymermembranen für die H2‐Trennung und ‐Aufreinigung.