Catalytic conversion of CH4 and CO2 to synthesis gas on Ni/SiO2 catalysts containing Gd2O3 promoter

A series of Ni/SiO2 catalysts containing different amounts of Gd2O3 promoter was prepared, characterized by H2-adsorption and XRD, and used for carbon dioxide reforming of methane (CRM) and methane autothermal reforming with CO2 + O2 (MATR) in a fluidized-bed reactor. The results of pulse surface reactions showed that Ni/SiO2 catalysts containing Gd2O3 promoter could increase the activity for CH4 decomposition, and Raman analysis confirmed that reactive carbon species mainly formed on the Ni/SiO2 catalysts containing Gd2O3 promoter. In this work, it was found that methane activation and reforming reactions proceeded according to different mechanisms after Gd2O3 addition due to the formation of carbonate species. In addition, Ni/SiO2 catalysts containing Gd2O3 promoter demonstrated higher activity and stability in both CRM and MATR reactions in a fluidized bed reactor than Ni/SiO2 catalysts without Gd2O3 even at a higher space velocity.