Sorption‐Enhanced Mixed Matrix Membranes with Facilitated Hydrogen Transport for Hydrogen Purification and CO2 Capture

Mixed matrix membranes (MMMs) comprising size‐sieving fillers dispersed in polymers exhibit diffusivity selectivity and may surpass the upper bound for gas separation, but their performance is limited by defects at the polymer/filler interface. Herein, a fundamentally different approach employing a highly sorptive filler that is inherently less sensitive to interfacial defects is reported. Palladium nanoparticles with extremely high H₂ sorption are dispersed in polybenzimidazole at loadings near the percolation threshold, which increases both H₂ permeability and H₂/CO₂ selectivity. Performance of these MMMs surpasses the state‐of‐the‐art upper bound for H₂/CO₂ separation with polymer‐based membranes. The success of these sorption‐enhanced MMMs for H₂/CO₂ separation may launch a new research paradigm that taps the enormous knowledge of affinities between gases and nanomaterials to design MMMs for a wide variety of gas separations.