Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland; A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninskii pr. 31, Moscow 119991, Russia. [email protected]
Abhijit Dutta
Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
Yongchun Fu
Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
Juan Herranz
Electrochemistry Laboratory, Paul Scherrer Institut (PSI), CH-5232 Villigen, Switzerland
Veerabhadrarao Kaliginedi
Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
Akiyoshi Kuzume
Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
Anastasia A. Permyakova
Electrochemistry Laboratory, Paul Scherrer Institut (PSI), CH-5232 Villigen, Switzerland
Yohan Paratcha
Electrochemistry Laboratory, Paul Scherrer Institut (PSI), CH-5232 Villigen, Switzerland
Peter Broekmann
Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
Thomas J. Schmidt
Electrochemistry Laboratory, Paul Scherrer Institut (PSI), CH-5232 Villigen, Switzerland; Laboratory of Physical Chemistry, ETH Zürich, 8093 Zürich, Switzerland
The electrochemical reduction of CO2 has been extensively studied over the past decades. Nevertheless, this topic has been tackled so far only by using a very fundamental approach and mostly by trying to improve kinetics and selectivities toward specific products in half-cell configurations and liquid-based electrolytes. The main drawback of this approach is that, due to the low solubility of CO2 in water, the maximum CO2 reduction current which could be drawn falls in the range of 0.01–0.02 A cm–2. This is at least an order of magnitude lower current density than the requirement to make CO2-electrolysis a technically and economically feasible option for transformation of CO2 into chemical feedstock or fuel thereby closing the CO2 cycle. This work attempts to give a short overview on the status of electrochemical CO2 reduction with respect to challenges at the electrolysis cell as well as at the catalyst level. We will critically discuss possible pathways to increase both operating current density and conversion efficiency in order to close the gap with established energy conversion technologies.
