No abstract

The reaction of the partial oxidation of methane was investigated over Ni/La 2 O 3 catalysts prepared by impregnation. Two different reactors were used, a perfectly jet-stirred reactor and a fixed-bed reactor. The influences of nickel content, calcination temperature, reaction temperature, residence time, and contact time were investigated. Mechanistic information was derived from the comparison of the results obtained in both reactors. Characterization techniques such as X-ray diffraction, temperature-programmed oxidation, temperatureprogrammed reduction, and transmission electron microscopy were used to assess the state of the catalyst prior to and after the reaction.

A complete kinetic study of the partial oxidation of methane has been performed in a "catalytic jet-stirred reactor". The main goal of this study was to elucidate the interactions between gas-phase reactions and surface reactions and to propose a detailed heterogeneous-homogeneous mechanism. The catalyst used in this study was lanthanum oxide (La 2 O 3 ). Various kinetic parameters were considered, including the temperature, the residence time, the contact time, and the amount of catalyst. The results revealed a complex behavior. In this first part of the study, the experimental results are given and discussed.