Electrochemical synthesis of ammonia from N₂ and H₂O based on (Li,Na,K)₂CO₃-Ce_0.8Gd _0.18Ca_0.02O_2-δ composite electrolyte and CoFe₂O₄ cathode

Electrochemical synthesis of ammonia from water vapour and nitrogen was investigated using an electrolytic cell based on CoFe₂O ₄-Ce0_.8Gd_0.18Ca_0.02O _2-δ (CFO-CGDC), CGDC-ternary carbonate composite and Sm _0.5Sr_0.5CoO_3-δ-Ce_0.8Gd _0.18Ca_0.02O_2-δ (SSCo-CGDC) as cathode, electrolyte and anode respectively. CoFe₂O₄, CGDC and SCCo were prepared via a combined EDTA-citrate complexing sol-gel and characterised by X-ray diffraction (XRD). The AC ionic conductivities of the CGDC-carbonate composite were investigated under three different atmospheres (air, dry O ₂ and wet 5% H₂-Ar). A tri-layer electrolytic cell was fabricated by a cost-effective one-step dry-pressing and co-firing process. Ammonia was successfully synthesised from water vapour and nitrogen under atmospheric pressure and the maximum rate of ammonia production was found to be 6.5 × 10^-11 mol s^-1 cm^-2 at 400 C and 1.6 V which is two orders of magnitude higher than that of previous report when ammonia was synthesised from N₂ and H₂O at 650 C.