Preparation of Silicon Carbide Supported Iron Catalysts and their Catalytic Activities in Hydrogen Production by Ammonia Decomposition

In this study, silicon carbide (SiC) was prepared from sol-gel process combined with subsequent carbothermal reaction. Then through hydrothermal method synthesized xFe/SiC-700 and 30Fe/SiC-T catalysts. The catalysts were characterized by XRD, SEM/TEM, XPS, and H2-TPR. The ammonia decomposition performances of the catalysts were assessed in a fixed-bed reactor. Tests revealed that SiC has a high specific surface area and can evenly diffuse Fe2O3 nanoparticles, thus exposing more active sites and raising the adsorption capacity of catalysts surface. The interaction of Fe2O3 and SiC is stronger, the catalyst activity is better. The surface basicity of catalyst is higher, decomposition ability of ammonia is stronger. 30Fe/SiC-700 catalyst has the best activity among the synthesized catalysts for hydrogen production by ammonia decomposition. The ammonia conversion rate can reach up to 90.16%, and the hydrogen generation can rate reach up to 30.19 mmol<middle dot>min-1<middle dot>gcat-1 at 600 degrees C at 30,000 mL<middle dot>gcat-1<middle dot>h-1. Moreover, the catalytic activity is efficient and stable after continuous reaction at 600 degrees C for 160 h.Graphical AbstractAmmonia decomposition: The silicon carbide supported iron oxide catalyst was prepared, which effectively cracked ammonia to produce COX-free H2.