Abstract
Natural rock weathering can permanently store CO2 as solid carbonates, but the process is slow. Here, we demonstrate a continuous-flow electrochemical reactor that captures and stores CO2 as inert carbonate minerals. This weathering electrolyzer accelerates rock weathering by electrolytically generating H+ and OH– in chambers separated by a Ca2+-selective membrane. The H+ decomposes silicates into reactive Ca2+ species, while OH– reacts with CO2 and Ca2+ to form CaCO3. This approach enables CO2 mineralization from both flue gas and air without isolating CO2 from conventional capture units.