Ultrapermeable Gel Membranes Enabling Superior Carbon Capture

Abstract Membrane technology is rapidly gaining broad attraction as a viable alternative for carbon capture to mitigate increasingly severe global warming. Emerging CO 2 ‐philic membranes have become crucial players in efficiently separating CO 2 from light gases, leveraging their exceptional solubility‐selectivity characteristics. However, economic and widespread deployment is greatly dependent on the boosted performance of advanced membrane materials for carbon capture. Here, we design a unique gel membrane composed of CO 2 ‐philic molecules for accelerating CO 2 transportation over other gases for ultrapermeable carbon capture. The molecular design of such soft membranes amalgamates the advantageous traits of augmented permeation akin to liquid membranes and operational stability akin to solid membranes, effectively altering the membrane's free volume characteristics validated by both experiments and molecular dynamics simulation. Surprisingly, gas diffusion through the free‐volume‐tuned gel membrane undergoes a 9‐fold improvement without compromising the separation factor for the superior solubility selectivity of CO 2 ‐philic materials, and CO 2 permeability achieves a groundbreaking record of 5608 Barrer surpassing the capabilities of nonfacilitated CO 2 separation materials and exceeding the upper bound line established in 2019 even by leading‐edge porous polymer materials. Our designed gel membrane can maintain exceptional separation performance during prolonged operation, enabling the unparalleled potential of solubility‐selective next‐generation materials towards sustainable carbon capture.