Investigation of the structure, acidity, and catalytic performance of CuO/Ti_0.95Ce_0.05O₂ catalyst for the selective catalytic reduction of NO by NH₃ at low temperature

详细信息    查看全文

• 作者：Xiaojiang Yao ; Lei Zhang ; Lulu Li ; Lichen Liu ; Yuan Cao ; Xian Dong ; Fei Gao ; Yu Deng ; Changjin Tang ; Zhuo Chen ; Lin Dong ; Yi Chen
• 关键词：CuO/Ti0.95Ce0.05O2 catalyst ; Coordination structure ; Electron interaction ; Surface acidity ; NH3-SCR model reaction
• 刊名：Applied Catalysis B: Environmental
• 出版年：5 May, 2014
• 年：2014
• 卷：150-151
• 期：Complete
• 页码：315-329
• 全文大小：2949 K

文摘

Anatase TiO₂, Ti_0.95Ce_0.05O₂ solid solution, and CeO₂ were synthesized by inverse co-precipitation method, and then used as supports to prepare CuO/TiO₂, CuO/Ti_0.95Ce_0.05O₂, and CuO/CeO₂ catalysts through incipient-wetness impregnation method. The obtained samples were investigated in detail by means of N₂-physisorption, XRD, LRS, H₂-TPR, XPS, NH₃-TPD, and in situ DRIFTS technologies. Furthermore, NH₃-SCR of NO in the presence of excess oxygen was chosen as a model reaction to evaluate the catalytic performances of these samples. The obtained results indicate that the incorporation of Ce⁴⁺ into the lattice of anatase TiO₂ leads to the formation of unstable distorted octahedral coordination structure of Cu²⁺ in CuO/Ti_0.95Ce_0.05O₂ catalyst and the enhancement of the electron interaction between copper oxide species and Ti_0.95Ce_0.05O₂ support through the redox cycles of Cu²⁺ + Ce³⁺ 鈫?#xA0;Cu⁺ + Ce⁴⁺ and Cu²⁺ + Ti³⁺ 鈫?#xA0;Cu⁺ + Ti⁴⁺, which are beneficial to the formation of more Lewis acid sites on the surface of CuO/Ti_0.95Ce_0.05O₂ catalyst and the activation of reactant molecules to generate more NH₄NO₂ species, all of these may promote the enhancement of catalytic performance for NH₃-SCR of NO in the presence of excess oxygen. Finally, a possible reaction mechanism (schematic diagram) is tentatively proposed to further understand this model reaction.