Sm_1.5Sr_0.5MO₄ (M=Ni, Co, Fe) Cathode Catalysts for Ammonia Synthesis at Atmospheric Pressure and Low Temperature

Sm_1.5Sr_0.5MO₄ (M=Ni, Co, Fe) (SSM) catalysts were prepared by a sol-gel method and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Ammonia was synthesized from wet hydrogen and dry nitrogen at atmospheric pressure and low temperature (25–100 °C) with applied voltage, using SSM as a cathode, Ni-Ce_0.8Sm_0.2O_2−δ (Ni-SDC) as an anode, and silver-platinum film as a current collector, Nafion proton exchange membrane as a proton permeating membrane. Several important factors on ammonia synthesis were investigated and the optimal synthetic temperature was found, at which the highest rate of evolution of ammonia was up to 1.05×10⁻⁸ mol·cm⁻²·s⁻¹.