Preparation and characterisation of Cr-Co spinels for methane oxidation in presence of sulphur compounds

Abstract

Three different Cr-Co spinels were prepared and tested as catalysts for the oxidation of methane in the presence of SO 2 , a typical catalyst poison. The spinels were prepared from nitrate precursors using a co-precipitation method, followed by calcining at three different temperatures, (400, 600 and 800 °C) for 5 hours. Characterisation results indicate that the catalyst calcined at 800 °C presents a structure of pure spinel, whereas the presence of single oxides is observed in the catalyst calcined at 600 °C, and the catalysts calcined at 400 °C presents a very complex structure (probably a mixture of several single and binary oxides). Experiments show an important influence of calcining temperature on the catalyst performance. In absence of SO 2 , catalysts calcined at 400 °C and 600 °C performs similarly, whereas the activity of the catalysts calcined at 800 °C is worse. When sulphur compounds were added to the feed, catalyst calcined at 600 °C deactivated faster than the other two catalysts.