Ru-supported lanthania-ceria composite as an efficient catalyst for COx-free H2 production from ammonia decomposition

Abstract Ru doped on a series of LaxCe1-xOy composites by the deposition-precipitation (DP) method was studied in NH3 decomposition to generate COx-free H2. N2 physisorption, CO chemisorption, XRD, XPS, XAS, ICP-OES, HAADF-STEM, TPR, and TPD analysis were used to investigate the catalyst properties and to elucidate the beneficial properties for the reaction. Density functional theory (DFT) calculations provided insights into how the La addition promoted the high recombinative N2 desorption capacity leading to the high NH3 decomposition activity of the Ru-based catalysts at low temperatures. Among the tested catalysts, Ru/La0.33Ce0.67 exhibited superior catalytic activity and excellent stability. This study provides direct proof that the combination of the relatively small Ru size with strong interaction with the composite LaxCe1-xOy by the DP method and the optimized acidity–basicity property for the enhancement of both H2 and N2 desorption is essential to the development of Ru-based catalysts for NH3 decomposition.