Effect of CeO_2 and CaO Promoters on Ignition Performance for Partial Oxidation of Methane over Ni/MgO-Al_2O_3 Catalyst

摘要

The effect of CeO_2 and CaO promoters on the ignition performance over Ni/MgO-Al_2O_3 catalyst for the partial oxidation of methane (POM) to synthesis gas was investigated. It was found that the POM reaction could not be ignited over 1wt%Ni/MgO-Al_2O_3 catalyst without the promoters in the temperature range from 773 K to 1073 K. CeO_2 and CaO promoters enhanced the ignition performance and the POM reactivity of 1wt%Ni/MgO-Al_2O_3 catalyst remarkably. Moreover, the improving effect became greater with the increase of the promoter content under the investigated reaction"conditions. The modification effects of CeO_2 and CaO promoters were closely related to the concentration and reducibility of the surface and bulk oxygen species.