Ruthenium Ammonium Chloride as a Precursor for the Preparation of High Activity Catalysts for Ammonia Synthesis

Ruthenium ammonium chloride, Ru(NH3)5Cl3, was prepared by the chemical reaction of ruthenium chloride with hydrazine hydrate and used as a novel ruthenium precursor for the preparation of activated carbon (AC)-supported Ru catalysts for ammonia synthesis. The results from TEM and CO chemisorption show that the Ru nanoparticles on the RuN/AC catalyst prepared from the Ru(NH3)5Cl3 precursor have much higher dispersion and more uniform size distribution than that on the Ru/AC catalyst from the RuCl3 precursor. The activity of the RuN/AC catalyst for ammonia synthesis was increased by more than 10% compared with the Ru/AC catalyst under the reaction conditions of 10 MPa and 10 000 h−1.