Acta Phys. -Chim. Sin. ›› 2003, Vol. 19 ›› Issue (06): 492-497.doi: 10.3866/PKU.WHXB20030603

• ARTICLE • Previous Articles     Next Articles

Role of Ce on Selective Oxidation of Propane to Acrolein over Ce-Ag-Mo-P-O Catalysts

Zhang Xin;Wan Hui-Lin;Weng Wei-Zheng;Yang Le-Fu;Yi Xiao-Dong   

  1. State Key Laboratory of C1 Chemistry and Technology,Department of Chemistry,Tsinghua University,Beijing 100084;
  • Received:2002-09-13 Revised:2002-11-20 Published:2003-06-15
  • Contact: Zhang Xin

Abstract: Role of Ce on the catalytic performance of Ce-Ag-Mo-P-O catalyst in selective oxidation of propane to acrolein was investigated.In order to establish the relationship between the catalytic performance and properties,the properties of Ag0.3Mo0.5P0.3Ox and Ce-doped Ag0.3Mo0.5P0.3Ox catalysts have been comparatively characterized by BET,XRD,H2-TPR,O2-TPD,C3H8-TPD and EPR.The addition of Ce to Ag0.3Mo0.5P0.3Ox catalyst distinctly improved the conversion of propane and the selectivity of acrolein.Ce0.1 Ag0.3Mo0.5P0.3Oy catalyst exhibited the highest selectivity and yield of acrolein in this reaction.The activation energy of propane oxidation was lower on the Ce0.1 Ag0.3Mo0.5P0.3Oy than on the Ag0.3Mo0.5P0.3Ox catalyst.Propene was a possible intermediate for the formation of acrolein in selective oxidation of propane on these catalysts.The proper addition of Ce enhanced the conversion of intermediate propene to acrolein.On the other hand,the addition of Ce improved the reducibility and Mo5+/Mo6+ ratio,furthermore,it caused a stronger adsorption of propane on the catalysts.The addition of Ce to the catalysts modified the properties by the formation of redox cycle “Ce3++Mo6+Ce4++Mo5+” in the catalysts.Such modification determined the catalytic performance of the catalysts in selective oxidation of propane to acrolein.

Key words: Propane, Selective oxidation, Acrolein, Reducible properties, Mo5+/Mo6+ molar ratio, Promoter Ce