Multi-Functional Polymer Membranes Enable Integrated CO₂ Capture and Conversion in a Single, Continuous-Flow Membrane Reactor under Mild Conditions

Herein, we present a membrane-based system designed to capture CO 2 from dilute mixtures and convert the captured CO 2 into value-added products in a single integrated process operated continuously under mild conditions. Specifically, we demonstrate that quaternized poly(4-vinylpyridine) (P4VP) membranes are selective CO 2 separation membranes that are also catalytically active for cyclic carbonate synthesis from the cycloaddition of CO 2 to epichlorohydrin. We further demonstrate that quaternized P4VP membranes can integrate CO 2 capture, including from dilute mixtures down to 0.1 kPa of CO 2, with CO 2 conversion to cyclic carbonates at 57 °C and atmospheric pressure. The catalytic membrane acts as both the CO 2 capture and conversion medium, providing an energy-efficient alternative to sorbent-based capture, compression, transport, and storage. The membrane is also potentially tunable for the conversion of CO 2 to a variety of products, including chemicals and fuels not limited to cyclic carbonates, which would be a transformative shift in carbon capture and utilization technology.