物理化学学报 >> 2014, Vol. 30 >> Issue (1): 157-163.doi: 10.3866/PKU.WHXB201311271

催化和表面科学 上一篇    下一篇

铜物种对Cu/Fe2O3水煤气变换反应催化剂性能的影响

林性贻, 马俊涛, 陈崇启, 詹瑛瑛, 郑起   

  1. 福州大学化肥催化剂国家工程研究中心, 福州 350002
  • 收稿日期:2013-09-02 修回日期:2013-11-27 发布日期:2014-01-01
  • 通讯作者: 林性贻 E-mail:linxingyi@fzu.edu.cn
  • 基金资助:

    福建省教育厅A类科技项目(JA08021)

Influence of Copper Species on Performance of Cu/Fe2O3 Catalysts for Water Gas Shift Reaction

LIN Xing-Yi, MA Jun-Tao, CHEN Chong-Qi, ZHAN Ying-Ying, ZHENG Qi   

  1. National Engineering Research Center of Chemical Fertilizer Catalyst, Fuzhou University, Fuzhou 350002, P. R. China
  • Received:2013-09-02 Revised:2013-11-27 Published:2014-01-01
  • Contact: LIN Xing-Yi E-mail:linxingyi@fzu.edu.cn
  • Supported by:

    The project was supported by the Education Department of Fujian Province Class A Science & Technology Program, China (JA08021).

摘要:

采用共沉淀法制备了系列铜负载量不同的Cu/Fe2O3水煤气变换(WGS)催化剂,并考察了铜负载量对催化剂结构和水煤气变换反应性能的影响. 结果表明,Cu/Fe2O3催化剂呈现出良好的水煤气反应性能,当CuO质量分数为20%时,催化剂的WGS性能最优,250 ℃时CO转化率高达97.2%,同时热稳定性也最好. 运用X射线粉末衍射(XRD)、N2物理吸脱附和H2程序升温还原(H2-TPR)等手段对Cu/Fe2O3催化剂的物相、织构特征及还原性能进行了表征,结果表明,CuFe2O4物种的存在极大地改善了催化剂的还原性能和WGS反应活性. 这是由于CuFe2O4特殊的尖晶石结构有利于Cu微晶的稳定;同时,CuFe2O4在低温下即被还原为单质铜,有利于促进催化剂体系中电子的转移. 此外,通过(NH4)2CO3溶液处理,研究了独立相CuO对Cu/Fe2O3催化剂WGS反应性能的影响,结果发现,独立相CuO的存在,有利于H原子在各组分传递,从而促进催化剂的CuFe2O4的还原,改善Cu/Fe2O3催化剂的WGS反应性能.

关键词: 水煤气变换, Cu/Fe2O3催化剂, 铜负载量, CuFe2O4

Abstract:

A series of Cu/Fe2O3 catalysts with different Cu loadings were prepared using a co-precipitation method, and the relationship between their structures and catalytic activities for the water gas shift (WGS) reaction was carefully examined. It was found that the as-prepared Cu/Fe2O3 catalysts exhibit excellent WGS performances, in particular, the one containing 20% (w) CuO (CF-20) shows the best catalytic activity, with CO conversion of 97.2% at 250 ℃. Its catalytic stability is also outstanding during the temperature range of 250-400 ℃. X-ray diffraction (XRD), N2 physisorption, and H2 temperature program reduction (H2-TPR) techniques were used to characterize the crystal phases, textures, and reduction properties of the Cu/Fe2O3 catalysts. The results show that the generation of CuFe2O4, which has a spinel structure in stabilizing Cu microcrystals and is easier to be reduced at low temperature, resulting in enhancing their reduction properties and facilitating electrons transfer between Cu and Fe2O3, thus greatly improving the catalytic performance. Furthermore, (NH4)2CO3 solution treatment of the as-prepared catalysts was performed to study the effect of bulk CuO existed in the Cu/Fe2O3 catalysts. The result suggests that the bulk CuO is favor for H atom transfer between Cu and Fe2O3, thus promoting the reduction of CuFe2O4, finally improving the catalytic performance.

Key words: Water gas shift, Cu/Fe2O3 catalyst, Copper loading, CuFe2O4

MSC2000: 

  • O643.3