In situ XRD, Raman, and TPR studies of CuO/Al₂O₃ catalysts for CO oxidation

详细信息	查看全文 | 推荐本文 |

• 作者：Meng-Fei Luo ; Ping Fang ; Mai He and Yun-Long Xie
• 关键词：CuO/Al₂O₃ ; High-temperature in situ XRD ; Raman spectroscopy ; Solid– ; solid interaction ; H₂-TPR ; CO oxidation
• 刊名：Journal of Molecular Catalysis A ; Chemical
• 出版年：2005
• 期刊代码：57_13811169
• 类别：ch
• 出版时间：2005
• 卷：239
• 期：1-2
• 页码：243-248
• 文件大小：506 K

摘要

A series of CuO/Al₂O₃ catalysts for CO oxidation were prepared by impregnation method with different loadings. CuO species and solid–solid interaction in CuO/Al₂O₃ catalysts were characterized by high-temperature in situ XRD, Raman spectroscopy and H₂-TPR techniques. CuAl₂O₄ is formed as a result of solid–solid interaction between CuO and Al₂O₃ when the calcination temperature reached 700 °C. Combine with XRD and Raman results, it is found that CuO species is on the surface region of CuO/Al₂O₃ catalysts, while CuAl₂O₄ is in the internal layer of CuO. The formation of CuAl₂O₄ inhibits CuO diffusing into Al₂O₃ support, which indicates that CuO can stabilize on the surface region of the catalysts at high temperatures. There are three H₂-TPR peaks namely, α₁, α₂ and β, which are attributed to the highly dispersed CuO species, bulk CuO species, and spinel CuAl₂O₄, respectively. The activity of CuO/Al₂O₃ catalysts for CO oxidation increased with increasing CuO loading. However, the increase of calcination temperature from 400 to 900 °C resulted in a decrease of the activity in CO oxidation. Combine with H₂-TPR and CO oxidation activity, it is supposed that the catalytic activity is related to both the highly dispersed CuO and bulk CuO.