Parametric Study on Ru/CeO2 Ammonia Decomposition Catalysts for Hydrogen Production

Ru/CeO2 is a promising catalyst for H2 production from ammonia decomposition due to the chemical properties of cerium dioxide and its particular interaction with Ru. In this work, Ru/CeO2 catalysts prepared by mechanochemical synthesis are studied in comparison with conventional impregnated catalysts to investigate the relevant parameters for catalytic ammonia decomposition. Different Ru precursors are used on CeO2 supports with varying surface areas, leading to a portfolio of catalysts with different characteristics such as CeO2 crystallite size, surface basicity, defectiveness, metal-support interaction, reducibility, spillover effect, metal particle dispersion and dimension, and actual Ru loading. The combination of catalytic results and different characterization techniques allows for a better understanding of the importance of the different factors that affect ammonia decomposition on Ru/CeO2 catalysts, highlighting the role of particle size and Ru─H bond strength, whose relative relevance, in turn, is dependent on Ru precursor and synthesis method.