Abstract
The electrochemical reduction of CO2 is a promising route to convert carbon emissions into valuable chemicals and fuels. In electrolyzers producing multi-carbon products, 70%–95% of the supplied CO2 is converted to (bi)carbonates, limiting the carbon efficiency of electrochemical CO2 conversion. These (bi)carbonate anions can be lost to the aqueous electrolyte, converted back to gaseous CO2 and diluted in the anode tail gas, and/or combined with alkali metal cations from the electrolyte to form solid salt precipitates. Here, we report a microchanneled solid electrolyte that allows for the recapture and recycling of (bi)carbonate ions before reaching the anode, reducing CO2 loss to ∼3%. We demonstrate CO2 electroreduction to multi-carbon products with 77% selectivity without the use of alkali metal cations, by incorporating fixed quaternary ammonium cations. This system simultaneously achieves near-zero CO2 loss, high selectivity toward multi-carbon products, and stable operation at an industrially relevant current density over 200 h.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1333-1343 |
| Number of pages | 11 |
| Journal | Joule |
| Volume | 6 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jun 15 2022 |
Funding
The authors acknowledge support from the Natural Sciences and Engineering Research Council (NSERC) of Canada and Natural Resources Canada\u2014Clean Growth Program. Support from Canada Research Chairs Program is gratefully acknowledged, as is support from an NSERC E.W.R. Steacie Fellowship to D.S. Y.X. acknowledges NSERC for their support through graduate scholarships. J.P.E. thanks NSERC, Hatch, and the Government of Ontario for their support through graduate scholarships. D.S. and E.H.S. supervised the project. Y.X. R.K.M. and J.P.E. designed experiments and analyzed results. Y.X. and R.K.M. carried out all the experiments. Y.X. and J.P.E. drafted the manuscript. S.L. performed COMSOL simulations. C.P.O. and C.M.G. performed large-scale experiments. Y.X. R.K.M. and M.F. synthesized catalysts. J.E.H. and A.R. performed product analysis. All authors discussed the results and assisted during manuscript preparation. The authors declare the following competing financial interest(s): there is a patent application pending, filed by the authors of this Letter and their institutions.
Keywords
- CO electrolysis
- CO reduction reaction
- CO utilization
- alkali metal cation free
- carbon efficiency
- electrocatalysis
- low CO loss
- microchanneled solid electrolyte
- multi-carbon production
ASJC Scopus subject areas
- General Energy
