aApplied Catalysis Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, Liaoning, PR China
bGraduate University of the Chinese Academy of Sciences, Beijing 100049, PR China
Abstract:
CeNi/SBA-15 and LaNi/SBA-15 catalysts were prepared by deposition–precipitation (DP) method and characterized by N2 physical adsorption, XRD, H2-TPR, H2-chemisorption and TEM. Their catalytic performances in the ammonia decomposition reaction were tested and compared with Ni/SBA-15 catalyst. Addition of cerium and lanthanum oxides to the Ni/SBA-15 catalyst caused some decrease of BET surface area and pore volume of the catalysts, but led to a promotion effect to their catalytic activity which was closely related to the ratio of Ce (La)/Ni. The highest conversion of ammonia could be obtained when the Ce (La)/Ni ratio was around 0.3. The promotion effect is more evident on CeNi/SBA-15(0.3) than on LaNi/SBA-15(0.3) catalyst under identical reaction conditions. The CeNi/SBA-15 and LaNi/SBA-15 catalysts show smaller nickel particle size and easier reducibility in comparison with the Ni/SBA-15 catalysts.