Surpassing Robeson Upper Limit for CO₂/N₂ Separation with Fluorinated Carbon Molecular Sieve Membranes

Rational design of robust and highly selective separation processes leading to an efficient sequestration of anthropogenic CO₂ is one of the most important problems, especially considering the effects of climate change. Unsurprisingly, the fabrication of highly selective CO₂ separation membranes, especially those capable of overcoming undesirable trade-off relationship between permeability and selectivity, is a vibrant and ever-growing field. However, there are only a handful examples of membranes that reportedly overcome the Robeson upper limit in CO₂ separations. In this work, we present an efficient strategy that addresses a rational design of materials that exhibit remarkable affinity toward CO₂ by introducing CO₂-philic fluorine-containing substituents into their structure, via a bottom up polymerization and pyrolysis approach and a precise control over the ultra-microporosity, resulting in some of the most efficient and promising CO₂ separation media reported thus far.