Effect of Fe_2O_3 Loading Amount on Catalytic Properties of Monolithic Fe_2O3/Ce_0.67Zr_0.33O_2 -Al_2O_3 Catalyst for Methane Combustion

摘要

Ce_(0.67)Zr_(0.33)O_2-Al_2O_3 solid solution was prepared by the co-precipitation method. Fe_2O_3-based catalysts supported on the solid solution were obtained by the impregnation method. The article revealed that the optimal loading amount of Fe_2O_3 on Ce_(0.67)Zr_(0.33)O_2-Al_2O_3 in our experimental condition for catalytic combustion of methane was 8% ( mass fraction). The prepared catalysts were characterized by BET, TPR, XRD analyses, and their catalytic activity was investigated after being calcined at 873 K and after being aged in water gas at 1273 K. When the loading amount of Fe_2O_3 was 8%( mass fraction), the catalyst held the highest activity, and the best temperature speciality and thermal stability. The complete-conversion temperature of methane for fresh and aged sample was 788 and 838 K, respectively. The range between the light-off temperature and the complete-conversion temperature was only 15 K. The characterization results of XRD indicated that Fe_2O_3 was well dispersed on the Ce_(0.67)Zr_(0.33)O_2-Al_2O_3 matrix. The results of BET and TPR were in good harmony with the catalytic activity results.