Partial oxidation of methane over Ni/Al2O3 catalyst calcined at ultrahigh temperatures

The Ni/Al2O3 catalyst calcined at ultrahigh temperatures (1200-1400 degrees C) was used in partial oxidation of methane (POM), and the Ni/Al2O3 catalyst retained high activity for POM after reduction. The X-ray diffraction result indicated that NiAl2O4 was formed when the catalyst was calcined at ultrahigh temperatures, and there was no phase transition in the temperature range. After the catalyst was reduced by H-2 at 950 degrees C, most of Ni in the catalyst existed as Ni-0, and the crystal size of Ni-0 was similar, which was confirmed by transmission electron microscopy. The excellent performance of the Ni/Al2O3 catalyst calcined at ultrahigh temperatures for the POM reaction was attributed to both the reducibility of NiAl2O4 and the similar crystal size of Ni-0. The higher the calcination temperature, the higher the reduction temperature for NiAl2O4.