化学学报 ›› 2007, Vol. 65 ›› Issue (10): 937-942. 上一篇    下一篇

研究论文

低贵金属Pt-Rh型三效催化剂空燃比性能的研究

郭家秀, 袁书华, 龚茂初, 张磊, 张丽娟, 赵明, 陈耀强*   

  1. (四川大学化学学院 成都 610064)
  • 投稿日期:2006-06-19 修回日期:2006-11-16 发布日期:2007-05-28
  • 通讯作者: 陈耀强

Study of Air/Fuel Ratio Performance of Low-Precious Metal Pt-Rh Three-Way Catalysts

GUO Jia-Xiu; YUAN Shu-Hua; GONG Mao-Chu; ZHANG Lei; ZHANG Li-Juan; ZHAO Ming; CHEN Yao-Qiang*   

  1. (College of Chemistry, Sichuan University, Chengdu 610064)
  • Received:2006-06-19 Revised:2006-11-16 Published:2007-05-28
  • Contact: CHEN Yao-Qiang

研究了以浸渍法制备的低贵金属Pt-Rh型三效催化剂对C3H8, CO, NO的催化活性. 主要考察了CeO2-ZrO2和BaO的添加对催化剂空燃比性能的影响, 通过氧化反应、水气变换和蒸汽重整的性能研究, 探讨了催化剂三效工作窗口扩大的原因. 结果表明, 催化剂中只添加CeO2-ZrO2时即具有优异的水气变换性能, 蒸汽重整在250 ℃左右发生, 并且在450 ℃以下时C3H8的转化率一直保持在20%左右; BaO添加到含有CeO2-ZrO2的催化剂中对水气变换和蒸汽重整则有明显的促进作用, 能进一步扩大催化剂的三效工作窗口; 催化剂中只添加CeO2-ZrO2时, 能明显提高催化剂对CO的氧化反应活性, 但对C3H8的氧化反应的影响则不明显; BaO和CeO2-ZrO2同时存在于催化剂中时, 能进一步提高CO的氧化反应活性, 对C3H8的氧化反应则没有明显的促进作用.

关键词: Pt-Rh, 三效催化剂, 水气变换, 蒸汽重整

The catalytic activities on C3H8, CO and NO of low-precious metal of Pt-Rh three-way catalysts prepared by impregnation were studied. The influence of adding CeO2-ZrO2 and BaO into catalysts on air-to-fuel ratio (A/F) was mainly investigated. The reason that A/F was broadened was studied by oxidization reaction, water-gas shift and steam reforming over catalysts. The results indicated that the catalyst merely containing CeO2-ZrO2 had excellent ability of water-gas shift, and steam reforming of C3H8 began to occur at 250 ℃ and maintained 20% of the conversion of C3H8 before 450 ℃. BaO was added to the catalyst containing CeO2-ZrO2, which could significantly promote water-gas shift and steam reforming and further broadened the three-way working-window of the catalyst. Only addition of CeO2-ZrO2 to the catalysts could promote oxidation reaction activity of CO, but the influence on oxidation of C3H8 was not obvious. Catalyst containing BaO and CeO2-ZrO2 could further promote oxidation reaction activity of CO but did not obviously promote oxidation of C3H8.

Key words: Pt-Rh, three-way catalyst, water-gas shift, steam reforming