Co-Electrolysis, Quo Vadis?

Abstract

This work focuses on the impact of reaction parameters of high-temperature co-electrolysis of carbon dioxide and water on the electrochemical performance and product gas distribution. Experiments have been performed with a conventional electrode (cathode) supported solid oxide cell. The electrochemical performance was investigated by I/V-curve measurements and impedance spectroscopy. The temperature was varied in the range of 750 to 900 °C. At 900 °C the impact of different feed gas compositions was investigated. The provided volumetric water vapor content was changed from 40 % with 20 % H2 up to 47.5 % with 5 % H2 in addition to the varied CO2 to H2O ratios 0, 1:1, 1:2 and 1:3. Parameter controlled syngas tailoring was shown by ramps of increasing current densities (at 0.001 mA·s-1) and coupled online product analysis at feed flow rates of 2, 3 and 6 nl·h-1, confirming its principle.