Production of syngas plus oxygen from CO2 in a gas-diffusion electrode-based electrolytic cell

Most of the research published in electrochemical CO2 reduction has been reported for half-cells, with little consideration of the overall system. However, it is necessary to consider the eventual involvement of full cells. We conducted CO2 reduction and water oxidation in a CO2-reducing full cell with larger geometric surface area (2 x 2 cm 2) and with a relatively small inter-electrode gap (1-2 mm) in order to minimize ohmic losses. The result was an ca. 1:1 CO/H-2 (v/v) gas ratio at a current density of 10 mA cm(-2) and a cell voltage of 3.05 V, producing O-2 at the counter electrode. Based on an enthalpic voltage of 1.36 V, this constitutes an overall energy efficiency of 44.6%. (C) 2002 Elsevier Science Ltd. All rights reserved.