CO2-mediated bicarbonate conversion to concentrated formate in a CEM-based electrolyzer

Abstract

Renewable energy-driven bicarbonate conversion to valuable chemicals presents an attractive strategy for mitigating CO₂ emissions, as bicarbonate can be efficiently generated from the capture of atmospheric CO₂ using alkaline solutions with reactive absorption. In this work, we present a CO₂-mediated bicarbonate conversion to pure formate using a cation exchange membrane-based electrolyzer with a 25 cm² electrode area. Our electrolysis achieved selectivities exceeding 75% for formate at a total current of 2.5 A, achieving formate concentrations up to 1.2 M and yields as high as 95% over extended periods. The techno-economic assessment confirmed the economic viability of the process, highlighting the potential for bicarbonate electrolysis as a sustainable method for producing valuable chemicals.