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以沉积-沉淀法制备了系列Au/CuMn催化剂,并对催化剂进行了XRD和XPS等表征,研究了Au负载量和催化剂焙烧温度对Au/CuMn催化剂性能的影响。实验结果显示,60℃烘干、Au理论负载量为3%的催化剂性能最佳,在50℃的反应条件下,NO的转化率达到72.4%,但催化剂失活较快。XPS分析显示,催化剂表面的Au3+与吸附氧物种Oads.是反应的活性中心,反应过程中催化剂表面氧化态Au3+与Oads.物种部分被还原,可能是催化剂失活的重要原因。另外,反应后在催化剂表面生成的亚硝酸盐、硝酸盐和碳酸盐等物种,覆盖了活性中心,也是导致催化剂失活的原因之一。
A series of Au / CuMn catalysts were prepared by deposition-precipitation method. The catalysts were characterized by XRD and XPS. The effects of Au loading and catalyst calcination temperature on the properties of Au / CuMn catalysts were investigated. The experimental results show that the catalyst with 3% of theoretical Au loading is the best when dried at 60 ℃. Under the reaction conditions of 50 ℃, the conversion of NO reached 72.4%, but the catalyst deactivation was faster. XPS analysis showed that Au3 + on the catalyst surface and Oads, an adsorbed oxygen species, were the active centers of reaction. The partial oxidation of Au3 + and Oads species on the surface of the catalyst during the reaction was partially reduced, which may be an important reason for catalyst deactivation. In addition, nitrite, nitrate and carbonate formed on the surface of the catalyst after the reaction covered the active sites, which was also one of the reasons for the deactivation of the catalyst.