(173b) Electrochemical Acid-Base Generators for Carbon Capture

In the PCET-driven system, we designed a three-chamber electrochemical cell achieving high current efficiency (>95%) at current densities of 20-200 mA cm⁻², producing concentrated acid and base (>1 M). By controlling proton and hydroxide crossover and optimizing fluidic designs, this system significantly reduced energy consumption and overcame limitations associated with traditional electrochemical CO₂ capture methods. Its efficacy was demonstrated in practical scenarios, including direct air capture, flue gas capture, and sustainable production of calcium hydroxide for green cement applications, highlighting its scalability and potential for renewable integration.

Additionally, we explored a non-PCET electrochemical system utilizing BPM-driven water dissociation to generate spatially separated acid and base without sensitivity to oxygen. By selecting robust redox mediators and optimizing electrolyte compositions, the system provided stable operation, high efficiency, and cost-effectiveness. We demonstrated effective direct air capture at high current densities, broadening the applicability of electrochemical carbon management solutions.

Collectively, these two systems offer promising pathways for sustainable, scalable, and energy-efficient carbon capture technologies, addressing critical challenges in carbon management through potentially low-cost electrochemical strategies.