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.