Long-term electrochemical carbon capture from diverse CO₂ sources with a recirculation mode

Electrochemical carbon capture offers a sustainable pathway for carbon management, yet current systems are hindered by low concentration of atmospheric carbon dioxide (CO₂), resulting in inefficiencies and limited stability. Here, we develop an electrochemical system employing a modular porous solid electrolyte (PSE) reactor for continuous, scalable carbon capture from diverse sources, including ambient air and flue gas, while regenerating high-purity CO₂ ( >99%) without additional chemical input through a recirculation mode. By leveraging oxygen evolution and reduction reactions (OER/ORR) and employing sodium (bi)carbonate as a reversible cyclic mediator, the system achieves continuous CO₂ capture from flue gas, delivering high Faradaic efficiencies for Na⁺ transport (~85%), and high carbon capture rates (3060 ml h^-1 at 10 A, 100 cm²). Notably, direct air capture is demonstrated using ambient air, showing a long-term stability of over 2000 hours while maintaining high carbon removal efficiency (>93%) at 30 mA cm^-2 and a large air treatment capacity (approximately 8820 kg_air day^-1 m^-2), thus contributing to the goal of achieving net-zero emissions.