Kinetic study of the catalytic dry reforming of CH4 with CO2 over La2-xSrxNiO4 perovskite-type oxides

Dry reforming of methane by carbon dioxide was investigated over La2-xSrxNiO4 perovskite-type oxides. The catalysts exhibited promising activity and very good stability at equimolar methane and carbon dioxide feed. Small amounts of Sr increase carbon deposition on the catalyst surface but addition of higher amounts of Sr suppresses coking and increases the CO2 conversion and the CO production. The kinetics of the reaction over LaSrNiO4 was also investigated by variation of the partial pressures of the reactants. The experimental data were fitted using the semi-empirical power rate law equation as well as using a Langmuir-Hinshelwood kinetic model. The activation energy for methane consumption estimated from both interpretations was similar to 41 kJ/mol. Lower values of activation energy estimated for carbon dioxide elimination, when compared to values obtained for methane consumption, correspond to higher reaction rate of CO2 in comparison to CH4 reaction rate. (C) 2010 Elsevier B.V. All rights reserved.