20222615 The effect of Calcination Temperature on the Catalytic Activity for Ammonia Decomposition over Ru/CeO2

Abstract

The study investigates the effect of calcination conditions on the performance of Ru/CeO2 catalysts of the NH3(Ammonia) decomposition. The catalysts were synthesized by changing the calcination temperatures from 400℃ to 800℃ and evaluated for their catalytic activity, stability, and structural properties. Initial conversion rates, long-term stability tests, and activation energy measurements revealed that the optimal calcination temperature for the CeO2 catalyst is 500℃, achieving high performance without the additional calcination. H2-TPR, CO- Chemisorption, XRD, ICP-OES, BET, XPS, SEM and STEM-EDS were utilized for Material characterization to explain the structural and compositional changes with calcination temperature variation. The study demonstrates that higher calcination temperatures lead to increased crystallite sizes, decreased surface area, and reduced dispersion, which negatively affect the catalytic performance. Additionally, a correlation between the oxidation state of Ru species and the reduction peak temperatures of RuOx was established, indicating that higher calcination temperatures increase oxidized Ru fraction, thus reducing catalytic efficiency. This comprehensive analysis provides insights into optimizing calcination conditions to enhance the catalytic activity of Ru/CeO2 for efficient ammonia decomposition.