Low temperature CO oxidation on Ni-promoted CuO-CeO2 catalysts

A series of Ce20Cu5NiyOx catalysts for CO oxidation at low temperature were prepared and characterized by N2 adsorption, X-ray diffraction, temperature-program reduction by H2, X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Ce20Cu5Ni0.4Ox exhibited the highest catalytic activity. The addition of NiO increased the amount of copper ions doped into the CeO2 matrix and gave more oxygen vacancies in ceria by the formation of a Ni-O-Ce solid solution. XPS results showed that large quantities of Cu+, Ce3+, and lattice oxygen existed in the fresh Ce20Cu5Ni0.4Ox catalyst. Cu+ ions in the catalyst can easily migrate to the ceria lattice to form a Cu-O-Ce solid solution, which enhanced the release of the lattice oxygen of the oxides under a reducing atmosphere. The high catalytic activity of Ce20Cu5Ni0.4Ox is due to the promoter giving increased amounts of Cu+ in the catalyst and the formation of solid solutions of both Cu-O-Ce and Ni-O-Ce.

摘要制备了一系列 CO 低温氧化的 Ce20Cu5NiyOx 催化剂, 并采用氮气低温物理吸附、X http://baike.baidu.com/view/290246.htm{射}衍衍射、程序升温还原、X http://baike.baidu.com/view/290246.htm{射}光光电子能谱以及拉曼光谱等手段对催化剂进行表征. 结果表明, Ce20Cu5Ni0.4Ox 催化剂活性最高. NiO 的添加可以使得较多的 Cu 物种掺杂到 CeO2 晶格中, 通过形成铈镍固溶体产生更多的氧空位. 表征结果显示, Ce20Cu5Ni0.4Ox 催化剂中存在大量的 Cu+, Ce3+及晶格氧, 催化剂中的 Cu+ 很容易进入到氧化铈晶格, 形成 Cu-O-Ce 固溶体, 从而增强了在还原气氛下晶格氧的释放能力. Ce20Cu5Ni0.4Ox 催化剂高的催化活性主要归因于大量 Cu+以及形成的 Cu-O-Ce 和 Ni-O-Ce 固溶体.

Graphical AbstractThe high catalytic activity of Ni-promoted CuO-CeO2 is due to the promoter giving increased amounts of Cu+ in the catalyst and the formation of solid solutions of Cu-O-Ce and Ni-O-Ce.Figure optionsDownload as PowerPoint slide