Electrochemical synthesis of ammonia using a cell with a Nafion membrane and SmFe0.7Cu0.3−x Ni x O3 (x = 0−0.3) cathode at atmospheric pressure and lower temperature

Abstract

Samaria-doped ceria Ce0.8Sm0.2O2- δ (SDC) and SmFe0.7Cu0.3- x Ni x O3 have been synthesized by the sol-gel method and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The electrochemical synthesis of ammonia was investigated at atmospheric pressure and low temperature, using the SFCN materials as the cathode, a Nafion mem-brane as the electrolyte, nickel-doped SDC (Ni-SDC) as the anode and silver-platinum paste as the current collector. Ammonia was synthesized from 25 to 100℃ when the SFCN materials were used as cathode, with SmFe0.7Cu0.1Ni0.2O3 giving the highest rates of ammonia formation. The maximum rate of evolution of ammonia was 1.13 × 10-8 mol·cm-2·s-1 at 80℃, and the current efficiency reached as high as 90.4%.