CO2 electroreduction favors carbon isotope 12C over 13C and facilitates isotope separation
Magda H. Barecka,
Mikhail K. Kovalev,
Marsha Zakir Muhamad,
Hangjuan Ren,
Joel W. Ager,
Alexei A. Lapkin
Affiliations
Magda H. Barecka
Department of Chemical Engineering, Northeastern University, 360 Huntington Avenue, Boston, MA 02215, USA; Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, MA 02215, USA; Cambridge Centre for Advanced Research and Education in Singapore, CARES Ltd. 1 CREATE Way, CREATE Tower #05-05, Singapore 138602, Singapore; Corresponding author
Mikhail K. Kovalev
Cambridge Centre for Advanced Research and Education in Singapore, CARES Ltd. 1 CREATE Way, CREATE Tower #05-05, Singapore 138602, Singapore
Marsha Zakir Muhamad
Cambridge Centre for Advanced Research and Education in Singapore, CARES Ltd. 1 CREATE Way, CREATE Tower #05-05, Singapore 138602, Singapore
Hangjuan Ren
Cambridge Centre for Advanced Research and Education in Singapore, CARES Ltd. 1 CREATE Way, CREATE Tower #05-05, Singapore 138602, Singapore; Department of Chemistry, University of Oxford, Oxford OX1 3QR, UK
Joel W. Ager
Berkeley Educational Alliance for Research in Singapore (BEARS), Ltd, 1 CREATE Way, Singapore 138602, Singapore; Department of Materials Science and Engineering, University of California at Berkeley, Berkeley, CA 94720, USA; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
Alexei A. Lapkin
Cambridge Centre for Advanced Research and Education in Singapore, CARES Ltd. 1 CREATE Way, CREATE Tower #05-05, Singapore 138602, Singapore; Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
Summary: We discovered that CO2 electroreduction strongly favors the conversion of the dominant isotope of carbon (12C) and discriminates against the less abundant, stable carbon 13C isotope. Both absorption of CO2 in the alkaline electrolyte and CO2 electrochemical reduction favor the lighter isotopologue. As a result, 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 demonstrate enriching of the 13C fraction to ∼1.3% (i.e., +18%) in a single-pass reactor and propose a scalable and economically attractive process to yield isotopes of a commercial purity. Our finding opens pathways to both cheaper and less energy-intensive production of stable isotopes (13C, 15N) essential to the healthcare and chemistry research, and to an economically viable, disruptive application of electrolysis technologies developed in the context of sustainability transition.
