Hydrogen production by steam reforming of propane using supported nickel over ceria-silica catalysts

The effect of silica molar content on the performance of Ni/CeO2-SiO2 during the steam reforming of propane was investigated. Nickel precursors supported over ceria-silica with different molar contents of ceria:silica (65:35, 75:25, 85:15 and 100:0) were synthetized and named Ni65CS, Ni75CS, Ni85CS and NiCe, respectively. BET surface area and in situ XRD results showed that a higher silica molar content in the support contributes to an increase in the surface area and to smaller Ni average crystallite size. Temperature Programmed Reduction and in situ X-ray absorption near edge spectroscopy indicate a direct relationship between the silica molar content on the metal-support interaction and ceria dispersion and reducibility. Ni65CS and Ni75CS had lower carbon accumulation rate than the other catalysts, as demonstrated by thermogravimetric analysis. Ni75CS presented the highest conversion (around 75%) during catalytic tests at 600 degrees C and did not suffer from deactivation after 25 h. Based on the results, the optimum ceria:silica content in the support was 75:25, since this produced a more stable catalyst and smaller carbon deposition.

Automated summary

The study found that the silica molar content in Ni/CeO2-SiO2 catalyst significantly affects its performance, with higher silica content leading to larger surface area and smaller Ni crystallite size. Silica content also influences the metal-support interaction, ceria dispersion, and reducibility. Experimental results showed that Ni75CS catalyst performed the best during propane steam reforming.