Investigation of Ni/Ce–ZrO2 catalysts in the autothermal reforming of methane

Nickel catalysts supported on α-Al2O3, CeO2, ZrO2 and Ce–ZrO2 were investigated in the autothermal reforming of methane. Ce–ZrO2 supports formed a solid solution and presented better oxygen storage capacity per unit of mass of Ce when compared to CeO2. Diffuse reflectance UV–Vis spectroscopy spectra and temperature-programmed reduction profiles, showed the presence of Ni2+ in tetrahedral and octahedral geometries for catalysts supported on mixed oxides. Temperature-programmed surface reaction experiments showed that the catalytic activity for autothermal reforming is proportional to the amount of metallic sites on the surface. However, when operating under severe coking conditions, catalysts with a higher oxygen storage capacity were more stable in the autothermal reforming of methane. Time-differential angular correlation experiments provided an atomic view on how the mobility of oxygen on CeZrO2 is enhanced by the presence of Ni, which increases the stability of the catalyst.