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

Abstract

A series of Ce 20 Cu 5 Ni y O x catalysts for CO oxidation at low temperature were prepared and characterized by N 2 adsorption, X-ray diffraction, temperature-program reduction by H 2 , X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Ce 20 Cu 5 Ni 0.4 O x exhibited the highest catalytic activity. The addition of NiO increased the amount of copper ions doped into the CeO 2 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 + , Ce 3+ , and lattice oxygen existed in the fresh Ce 20 Cu 5 Ni 0.4 O x 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 Ce 20 Cu 5 Ni 0.4 O x 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. 制备了一系列 CO 低温氧化的 Ce 20 Cu 5 Ni y O x 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, Ce 20 Cu 5 Ni 0.4 O x 催化剂活性最高. NiO 的添加可以使得较多的 Cu 物种掺杂到 CeO 2 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, Ce 20 Cu 5 Ni 0.4 O x 催化剂中存在大量的 Cu + , Ce 3+ 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. Ce 20 Cu 5 Ni 0.4 O x 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. The high catalytic activity of Ni-promoted CuO-CeO 2 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.