Solvothermal processed Ru-based catalyst enhances ammonia decomposition efficiency for carbon-free H2 production

Ammonia (NH 3 ) decomposition is a promising route for on-demand, CO x -free hydrogen generation, but it requires highly active and durable catalysts to operate efficiently at low temperatures. In this study, Ru/CeO 2 catalysts were synthesized using solvothermal (ST), deposition-precipitation (DP), and wet-impregnation (WI) methods to elucidate how the Ru fabrication method affects Ru state and metal-support interactions in the catalytic NH 3 decomposition. The ST route using ethylene glycol produced the most active catalyst (RC-ST), delivering a H 2 formation rate of 1319.6 mmol H2 /min/g Ru at 450 °C and WHSV = 30,000 mL NH3 /g cat. /h with excellent stability over 100 h, positioning RC-ST as a promising Ru/CeO 2 catalyst architecture for further optimization. Here, the solvothermal route enhances Ru dispersion and accessible Ru sites as the dominant origin of the enhanced apparent activity. In addition, a higher density of Ru-O V -Ce 3+ interfacial defects in RC-ST correlates with a lower N 2 desorption temperature and may further support the catalytic improvement.