Basicity Modification of the Yttrium oxide supported ruthenium nanoparticles catalysts to enhance catalytic performance for hydrogen production from ammonia decomposition

Abstract Hydrogen production from ammonia decomposition is a key green hydrogen preparation technology, and the supported ruthenium (Ru) catalyst is one of the most optimally active ammonia decomposition catalysts nowadays, and the basicity of the support has a significant effect on the performance of ruthenium catalysts. In this paper, a potassium-modified yyttrium support (K-Y₂O₃)-supported Ru nanoparticle catalyst was successfully prepared by the precipitation deposition method, and the hydrogen production rate of the 3% Ru/K-Y₂O₃ catalyst was up to 31.49 mmol gcat⁻¹ min⁻ ¹ under 450°C with a gas hour space velosity of 30,000 mL gcat⁻¹ h⁻ ¹, which was an order of magnitude higher than that of K-4.6% Ru/MgO catalyst. Moreover, the catalyst activity did not decay significantly during a 120 h test. Combined with TEM, NH₃-TPD, XPS, CO₂-TPD and other characterization methods, it was found that the presence of K species enhanced the basicity of the support, promoted the reduction of Ru nanoparticles and surface Y₂O₃ supports, and increased the electron density of Ru nanoparticles and the oxygen vacancy concentration of the support, thus the Ru/K-Y₂O₃ catalysts had strong ammonia dissociation and nitrogen-binding desorption ability to enhance its performance in ammonia decomposition reaction.