XRD analysis. The XRD patterns of calcined Ni-based samples
prepared by different impregnation sequences are displayed in
Fig. 3(a). All samples exhibited the characteristic peaks of NiO at
43.3, 62.9 and 76.3, and the characteristic peaks of g-Al2O3 at 2q
angle of 37.2, 45.8 and 66.9. After the
adoption of Ce, the Ni-based catalyst samples showed not only the
peaks of g-Al2O3 and NiO, but also the characteristic reflections of
CeO2 at 2q angle of 28.5, 33.1 and 56.3.
Compared with Ni/Al2O3, the Ce-promoted catalysts showed the
slightly weaker intensity of NiO diffraction peaks at 2q angle of