The effects of cobalt and cerium promoters on hydrogen production performance of alumina‐supported nickel catalysts in propane steam reforming

Abstract

BACKGROUND: The effects of Co and Ce promoters on the performance of Ni (10 wt%)-Co (0.0, 2.75, 5.5 wt%)/Ce (0.0, 5.0, 10.0 wt%)-Al 2 O 3 catalysts have been studied for steam reforming of C 3 H 8 (SRP). In this work, Ni (NO 3) 2 and Co (NO 3) 2 are coimpregnated on the co-precipitated Al 2 O 3-CeO 2 supports. X-ray diffraction, N 2 adsorption-desorption, H 2-temperature-programmed reduction, high-resolution transmission electron microscopy, scanning electron microscopy and thermogravimetric/differential thermal analysis were accomplished to explain the SRP activity of the catalysts. The performance of the resulting catalysts was evaluated under the gas hourly space velocity (GHSV) = 45 000 mL h-1 g cat −1 , T = 600°C, steam/C 3 H 8 ratio (S/C) = 3 and P = 1 atm. RESULTS: The experimental findings revealed that Ce and Co promoters markedly improved the catalyst activity, stability and H 2 yield of Ni/Al 2 O 3 catalyst. The sample with 2.75 wt% Co and 10.0 wt% Ce showed highest C 3 H 8 conversion, while maximum yield of H 2 was obtained for catalyst containing 5.5 wt% Co and 5.0 wt% Ce. CONCLUSION: Higher loadings of Co decreased C 3 H 8 conversion and catalyst stability due to more coke formation on the catalyst surface, whereas Ce significantly improved catalyst resistance to coke deposition due to the enhanced Ni metal particles distribution over the support.