A novel method for preparation of doped Ba3(Ca1.18Nb1.82)O9−δ: Application to ammonia synthesis at atmospheric pressure

Complex perovskite-type oxides Ba3(Ca1.18Nb1.82)O9 (BCN18), Ba3CaZr0.5Nb1.5O9 (BCZN), and Ba3Ca0.9Nd0.28Nb1.82O9 (BCNN) were synthesized by a new wet chemical method and characterized by thermal analysis (TG-DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Using the sintered samples as solid electrolyte and silver-palladium alloy as electrodes, ammonia was synthesized from nitrogen and hydrogen at atmospheric pressure in the solid-state proton-conducting cell reactor. The rate of evolution of ammonia was up to 2.16×10−9 mol s−1 cm−2.