催化学报

催化学报 ›› 2012, Vol. 33 ›› Issue (3): 425-431.DOI: 10.1016/S1872-2067(11)60337-9

• 研究论文 • 上一篇    下一篇

La2O3 对 CuO/CeO2 水煤气变换反应催化剂微观结构及催化性能的影响

方星, 陈崇启, 林性贻*, 佘育生, 詹瑛瑛, 郑起   

  1. 福州大学化肥催化剂国家工程研究中心, 福建福州 350002
  • 收稿日期:2011-09-21 修回日期:2011-11-04 出版日期:2012-03-15 发布日期:2015-07-27

Effect of La2O3 on Microstructure and Catalytic Performance of CuO/CeO2 Catalyst in Water-Gas Shift Reaction

FANG Xing, CHEN Chongqi, LIN Xingyi*, SHE Yusheng, ZHAN Yingying, ZHENG Qi   

  1. National Engineering Research Center of Chemical Fertilizer Catalyst, Fuzhou University, Fuzhou 350002, Fujian, China
  • Received:2011-09-21 Revised:2011-11-04 Online:2012-03-15 Published:2015-07-27

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摘要： 以 La2O3 为助剂, 采用共沉淀法制备了具有良好催化活性和热稳定性的 CuO/CeO2-La2O3 水煤气变换反应催化剂, 其中, 当 La2O3 含量为 2 wt% 时, 催化剂的催化性能最为优异. 同时运用 X 射线衍射、N2 吸附-脱附、Raman 光谱、程序升温还原等手段, 研究了不同含量的 La2O3 对 CuO/CeO2 催化剂微观结构及催化性能的影响. 结果表明,La2O3助剂进入了载体 CeO2 的晶格并对 CuO/CeO2 催化剂的微观结构和催化性能产生了直接影响, 适量 La2O3的添加可以抑制 CuO 和 CeO2 晶格的长大、增强 CuO 与 CeO2 间的相互作用、提高催化剂的比表面积、促进 CeO2 载体中生成更多的氧空位, CuO/CeO2 催化剂的催化活性和热稳定性也明显改善.

关键词: 氧化铜, 氧化铈, 氧化镧, 水煤气变换反应, 氧空位, Raman 光谱

Abstract: The water-gas shift reaction was used to evaluate a series of La2O3 modified CuO/CeO2 catalysts that were prepared by a parallel co-precipitation method. The catalytic activity and thermal stability improved significantly upon the introduction of La2O3, and CuO/CeO2-La2O3 (2 wt%) gave the highest activity and had the best thermal stability. The microstructure of the as-prepared CuO/CeO2-La2O3 catalysts and/or the CeO2-La2O3 supports was characterized by X-ray diffraction, N2 physisorption, Raman spectroscopy, and temperature-programmed reduction. The results indicate that larger specific surface areas and smaller crystal sizes of CuO and CeO2 result in improved catalytic performance for the as-prepared catalysts. Moreover, the incorporation of La3+ into the ceria lattice promotes the generation of oxygen vacancies leading to a higher number of moderate copper oxides that interact with surface oxygen vacancies on the surface of the ceria. This enhances the activity and thermal stability of the CuO/CeO2 catalyst.

Key words: copper oxide, ceria, lanthanum oxide, water-gas shift reaction, oxygen vacancy, Raman spectroscopy