Ru/Al2O3 bead-shaped catalyst with La-Ce composite surface layer via direct surface gelation for enhanced ammonia decomposition

초록

In this study, we developed Ru-based bead catalysts (spherical, diameter = 3 mm) with enhanced activity and durability using a novel fabrication strategy that combines a direct surface gelation method (g-SM) and a bead surface pre-treatment (ST) to form thin and uniform La-Ce-modified layer with K promotion. The La-Ce layer functioned as an electron-donating support, while the promotion effect of potassium introduced during the ST and g-SM steps was further reinforced by the La-Ce layer with the simultaneous modulation of the Ru-support interface. Among the fabricated catalysts, Ru/LaCe-g/Al2O3-st demonstrated the highest catalytic activity with reduced approximately 1 wt% Ru and 0.4 wt% La-Ce loading level, achieving approximately 80 % NH3 conversion at approximately 500 degrees C and 6000 mLNH3 gcat. noticeable structural degradation. The enhanced performance was attributed to improved metal-support interactions and electron donation to Ru particles, resulting in the alleviation of N2 desorption.

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