Chinese Journal of Catalysis ›› 2012, Vol. 33 ›› Issue (3): 536-542.DOI: 10.3724/SP.J.1088.2012.10949

• Research papers • Previous Articles     Next Articles

Effects of Pr Doping on Structure and Catalytic Performance of Ru/CeO2 Catalyst for Ammonia Synthesis

LIN Jianxin*, ZHANG Liuming, WANG Ziqing, WANG Rong, WEI Kemei   

  1. National Engineering Research Center of Chemical Fertilizer Catalyst, Fuzhou University, Fuzhou 350002, Fujian, China
  • Received:2011-09-26 Revised:2011-11-04 Online:2012-03-15 Published:2015-07-27

Abstract: The Pr-doped ceria supported ruthenium catalyst Ru/CeO2-PrO2 for ammonia synthesis was prepared by a redox co-precipitation method. The obtained catalyst samples were characterized by N2 physisorption, X-ray diffraction, H2 temperature-programmed reduction, CO chemisorption, temperature-programmed desorption of nitrogen, field-emission scanning electron microscopy, high resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. The effects of Pr doping amount on the microstructure and catalytic properties of Ru/CeO2-PrO2 were investigated. The results showed that the composite oxide created form Pr-doped ceria has some influence on the Ru dispersion and surface texture. The activity test showed that the ammonia synthesis transformation frequency over the Ru/CeO2-PrO2 catalyst with 4% Pr was 12.13 × 10–2 s–1 at 10 MPa, 10000 h–1, and 425 ºC, which was 58% higher than that of Ru/CeO2. The improvement of electrical conductivity performance is the key factor for the higher catalytic activity.

Key words: praseodymium, ceria, ruthenium, supported catalyst, ammonia synthesis