Abstract:

Ce_xNi_0.5La_0.5-xO (CeNiLaO) catalysts were synthesized using a Ce-La composite oxide as the carrier via co-precipitation. They were applied in the oxidative steamreforming of glycerol (OSRG) in a fixed-bed reactor. The catalysts were characterized by X-ray diffraction (XRD), H₂-temperature-programmed reduction (H₂-TPR), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Xray photoelectron spectroscopy (XPS). The results showed that La₂O₃ improved the dispersion of metallic Ni and suppressed the sintering of metallic Ni particles; the lattice oxygen of CeO₂ inhibited and eliminated carbon deposition on the surface of the catalysts; and the substitution of some La³⁺ for Ce⁴⁺ ions induced a distortion of the lattice. The synergy of La₂O₃ and CeO₂ lessened the deactivation caused by the sintering and coke deposition and improved the catalytic performance. Among the catalysts with different molar ratios of Ce to La, Ce_0.4Ni_0.5La_0.1O had the best catalytic activity. The conversion of glycerol remained above 95% after a 210 h stability test, while a gaseous reformate of about 50% hydrogen could be steadily produced.

Key words: CeO₂, La₂O₃, Ni, Stability, Glycerol, Hydrogen production, Steam reforming