A Dual-Functional Membrane for CO2 Capture and Electrocatalytic Reduction.

Abstract

Carbon capture, utilization, and sequestration technologies are critical for limiting global temperature rise. CO2 capture and utilization are traditionally performed as separate unit operations. Integrating them requires using dual-functional materials and offers a promising pathway to overcome energy demand and cost limitations. In this study, we demonstrate the fabrication of an electrocatalytic membrane (eCatMem) by laser-induced graphene processing of a gas-separating membrane, enabling CO2 reduction to formate. The membrane exhibits CO2/N2 permselectivity of ~20, ensuring comparable performance when operating with pure CO2 or a 10% CO2/N2 gas mixture. The eCatMem achieves current densities of 10-50 mA/cm2 with a Faradaic efficiency of ~70% for formate production. This is the first of its kind demonstration of integrated membrane electrochemical reactive separation to form a liquid capture media that is also a product. This approach utilizes simple, low-cost materials and processes and offers a scalable way to integrate CO2 capture and utilization.