(384b) Extreme Isotope Discrimination Effect Associated with Electrochemical Carbon Capture

This talk will cover a fundamental discovery in the field of electrochemical separations. We demonstrated that the electrochemical capture and conversion of carbon dioxide strongly favours the dominant isotope of carbon (¹²C) and discriminates against the less abundant, stable carbon ¹³C isotope. We investigated the individual contribution of different steps involved in the process and provided an evidence that absorption of CO₂, electrochemical reduction, and dissolution of CO₂ in the alkaline electrolyte all favour the lighter isotope.Consequently, the stream of unreacted CO₂ leaving the electrolyzer has an increased ¹³C content, and the depletion of ¹³C in the product is several times greater than that of photosynthesis. Using a natural abundance feed, we experimentally demonstrate enriching of the ¹³C fraction to ~1.3% (+18%) in a single pass reactor, which significantly exceeds the performance of all known isotope separation methods. Our findings are important for the entire electrochemistry community, as this unexpectedly high isotope separation effect needs to be taken into consideration in all electrochemical carbon isotope labelling studies. Furthermore, the outcomes of our research should open pathways to more sustainable and less energy-intensive production of different stable isotopes essential to the healthcare and chemistry research.