Effect of calcination temperature on structure and performance of Ni/TiO2-SiO2 catalyst for CO2 reforming of methane

The influence of calcination temperature on the structure and catalytic behavior of Ni/TiO(2)-SiO(2) catalyst, for CO(2) reforming of methane to synthesis gas under atmospheric pressure, was investigated. The results showed-that the Ni/TiO(2) SiO(2) catalyst calcined at 700 degrees C had high and stable activity while the catalysts calcined at 550 and 850 degrees C had low and unstable activity. Depending on the calcination temperature, one, two, or three of the following Ni-containing species, NiO, Ni(2.44)Ti(0.72)Si(0.07)O(4), and NiTiO(3) were identified by combining the temperature programmed reduction (TPR) and X-ray diffraction (XRD) results. Their reducibility decreased in the sequence: NiO>Ni(2.44)Ti(0.72)Si(0.07)O(4)>NiTiO(3). It suggests that high and stable activities observed over the Ni/TiO(2)-SiO(2) catalyst calcined at 700 degrees C were induced by the formation of Ni(2.447)Ti(0.72)Si(0.07)O(4) and smaller NiO species crystallite size.