The kinetic behavior of the Ni/La2O3 catalyst in the reforming reaction of methane with carbon dioxide was investigated as a function of temperature and partial pressures of CH4 and CO2. The apparent activation energy of the reforming reaction was estimated to be 13.2 kcal/mol. It was also found that increase of the Hr partial pressure leads to a continuous enhancement of the rate of CO formation, due to the simultaneous occurrence of the water-gas shift reaction. The mechanism of the CH4/CO2 reaction has been investigated using steady-state isotopic tracing and transient experiments, as well as FTIR, XRD, XPS and HR-TEM techniques. Based on the mechanistic results, a kinetic model was developed, which was found to predict satisfactorily the kinetic measurements. Methane cracking and the surface reaction between C and oxycarbonate species, are suggested to be the rate determining steps of the CH4CO2 reaction over the Ni/La2O3 catalyst. (C) 2001 Elsevier Science B.V. All rights reserved.