Bench-scale electrochemical system for generation of CO and syn-gas

A flow cell based, bench-scale electrochemical system for generation of synthesis-gas (syn-gas) is reported. Sensitivity to operating conditions such as CO₂ flow, current density, and elevated temperature are described. By increasing the temperature of the cell the kinetic overpotential for the reduction of CO₂ was lowered with the cathode voltage at 70 mA cm^-2 decreased by 0.32 V and the overall cell voltage dropping by 1.57 V. This equates to an 18% increase in cell efficiency. By closely monitoring the products it was found that at room temperature and 70 °C the primary products are CO and H₂. By controlling the current density and the flow of CO₂ it was possible to control the H₂:CO product ratio between 1:4 and 9:1. The reproducibility of performing experiments at elevated temperature and the ability to generate syn-gas for extended periods of time is also discussed.