The electrochemical CO2
reduction reaction (CO2
RR) is a complex reaction which must be carried out in a highly selective and efficient manner. Many efforts are being taken to develop catalysts with improved reaction selectivity and efficiency and significant progress has been made in this area of research . However, CO2
RR kinetics, product identification and quantification are mostly carried out in half-cell configurations using liquid electrolytes. This fundamental approach of studying CO2
RR is limited by the low solubility of CO2
in water, the maximum CO2
reduction current reported in the literature is in the range of 0.01- 0.02 A/cm2
. In order to overcome the solubility problem and to reach higher operating current densities, CO2
reduction can be carried out in a co-electrolysis system where pure or diluted gaseous CO2
is used. Our research efforts were focused on the design of an electrochemical cell for co-elecrolysis operating at high-current densities with good product selectivity.
The most promising results were obtained when a bipolar membrane was used as the electrolyte. The experiments were conducted in a membrane electrolyzer-like configuration setup. Various gold type cathode electrode materials were tested. IrTiO2 was used as an anode material to catalyse the oxygen evolution reaction. The reaction products were analysed by on-line mass spectroscopy. The co-electrolyser performance and the selectivities of the various MEAs are examined in detail.
 J. Herranz, J. Durst, E. Fabbri, A. Patru, X. Cheng, A.A. Permyakova, T.J. Schmidt, Nano Energy 2016, 29, 4.
 J. Durst, A. Rudnev, A. Dutta, Y. Fu, J. Herranz, V. Kaliginedi, A. Kuzume, A.A. Permyakova, Y. Paratcha, P. Broekmann, T.J. Schmidt, Chimia 2015, 12, 69.
Financial support of this work by the Commission of Technology and Innovation Switzerland (CTI) and the Swiss Competence Center for Energy Research Heat and Electricity Storage are greatly acknowledged.