Acta Phys. -Chim. Sin. ›› 2016, Vol. 32 ›› Issue (7): 1801-1809.doi: 10.3866/PKU.WHXB201604081

• ARTICLE • Previous Articles     Next Articles

Effects of Zr Addition on CO and CH4 Catalytic Oxidation over PdO/PdO/Ce1-xPdxO2-δ Catalyst

Yong-Chang JIA,Shu-Yuan WANG,Lian MENG,Ji-Qing LU,Meng-Fei LUO*()   

  • Received:2015-12-29 Published:2016-07-08
  • Contact: Meng-Fei LUO E-mail:mengfeiluo@zjun.cn
  • Supported by:
    The project was supported by the National Natural Science Foundation of China(21203167);The project was supported by the National Natural Science Foundation of China(21173195);Zhejiang Province Public Technology Applied Research Projects, China(2013C31049)

Abstract:

PdO/PdO/Ce1-xPdxO2-δ (PdO/CP) and PdO/Ce1-x-yPdxZryO2-δ (PdO/CPZ) catalysts were prepared via a solution combustion method. The corresponding PdO/Ce1-xPdxO2-δ (CP) and Ce1-x-yPdxZryO2-δ (CPZ) catalysts were obtained by nitric acid treatment of the PdO/CP and PdO/CPZ catalysts to remove the surface PdO species. These catalysts were tested for CO and CH4 catalytic oxidation. The turnover frequencies (TOFs) of surface PdO and Pdn+ cations in the CP and CPZ solid solutions were calculated. The results showed that Zr addition in the PdO/CP catalyst had very different effects on CO and CH4 oxidation. A significant improvement in CO oxidation activity was observed over the Zr-containing catalysts; this could be related to the formation of smaller PdO particles on the surface of the PdO/CPZ catalyst and a higher oxygen vacancy concentration in the CPZ solid solution. For CH4 oxidation, Pdn + cations in the solid solution play a key role in the catalytic oxidation process. The penetration of Zr4+ cations into the CeO2 lattice decreased the amount of Pd2+ cations in the CPZ solid solution and thus inhibited the activities of the Zr-containing catalysts (PdO/CPZ and CPZ) for CH4 oxidation.

Key words: Zr, PdO, Oxygen vacancy, CO oxidation, CH4 oxidation

MSC2000: 

  • O643