Abstract A novel composite membrane consisting of an interconnected MOF scaffold coated with cross‐linked poly(ethylene glycol) (PEG) has been developed. As a result of its unique structure, the membrane shows an exceptional 18‐fold permeability enhancement as compared to pristine PEG membranes, without compromising the selectivity. This performance is unattainable with current mixed‐matrix membranes (MMMs). Our optimized membrane has a permeability of 2700 Barrer with a CO 2 /N 2 selectivity of 35, which surpasses the latest Robeson upper bound.