CsH ₂ PO ₄ as Electrolyte for the Formation of CH ₄ by Electrochemical Reduction of CO ₂

It has been shown that methane can be formed in high amounts by co-electrolysis of CO 2 and H 2 O using a nickel cathode, a CsH 2 PO 4 –SiC composite electrolyte and an IrO 2 anode. The experimental conditions were 300 °C and 8 bar. The maximum efficiency close to 100% for methane was obtained at a current density of 10–15 mA cm −2 . A small amount of hydrogen was formed as the only other product.