Kinetic and stability studies of Ru/La2O3 used in the dry reforming of methane

Abstract

The catalytic activity toward hydrogen production through the dry reforming of methane was determined for Ru supported on lanthanum oxide. The catalyst remained stable for more than 80 h in the 823-903 K temperature range and reactant partial pressure ratio (PCO2/PCH 4) equal to unity. However, a significant deactivation was observed during the kinetic measurements when the catalyst was exposed to P CO2/PCH4 > 1 at 823 K. In order to establish why the catalyst deactivated, the Ru reactivity in reductive and CO2 rich atmospheres was studied by in situ LRS and XPS spectroscopies. The partial re-oxidation of metallic Ru could be one of the factors that produce the catalyst deactivation. To perform the kinetic measurements, the temperature range and the partial pressure ratios were selected within the window where the Ru catalyst was stable. The kinetic data and supporting spectroscopic evidence is consistent with a mechanism in which the metal and the oxide play key roles in decomposing the paraffin and activating the CO2, respectively.