Syngas production: diverse H2/CO range by regulating carbonates electrolyte composition from CO2/H2O via co-electrolysis in eutectic molten salts

We present a novel sustainable method for the direct production of syngas (H-2 + CO) from CO2/H2O co-electrolysis using a hermetic device, to address the continuously increasing level of environmental carbon dioxide (CO2). All experiments were conducted using a two-electrode system with a coiled Fe cathode and coiled Ni anode in eutectic mixtures of binary and ternary carbonates with hydroxide in a 0.1 : 1 hydroxide/carbonate ratio. With an applied voltage of 1.6-2.6 V and an operating temperature of 500-600 degrees C, the H-2/CO product ratio was easily tuned from 0.53 to 8.08 through renewable cycling of CO2 and H2O. The Li0.85Na0.61K0.54CO3-0.1LiOH composite had the highest current efficiency among those tested, with an optimum value approaching similar to 93%. This study provides a promising technique for the electrochemical conversion of CO2/H2O to a controllable syngas feedstock that can be used in a broad range of industrial applications.