摘要
用TPR,DRS,TEM,XRD等技术研究了CuO/TiO_2催化剂活性组分CuO在TiO_2表面上的分散状态,并同催化剂CO氧化活性进行了关联。结果表明,CuO在TiO_2表面有分散和聚集两种状态,分散态CuO是CO氧化反应的主要活性位。由XRD相定量法测出CuO在TiO_2载体上的单层分散阈值为0.04g CuO/100m^2TiO_2。据此提出了CuO-TiO_2在界面处相互交联的几何模型,即Cu^(2+)插入TiO_2表面氧八面体空隙。
The states of CuO on TiO2 surface of CuO/TiO2 catalysts were studied by TPR, DRS, TEM, XRD techniques, and the states were correlate dwith the activity for CO oxidation of the catalysts. The threshold value of CuO monolayer dispersion was measured by X-ray diffraction quantitative analysis. It was found that there were dispersed and clustered CuO on TiO2 surface, and the dispersed CuO was the main active sites for CO oxidation. The threshold of monolayer dispersion was 0.04g CuO/100m2 TiO2. According to this value, an interf acial coherence model of CuO and TiO2 was suggested, i.e. cupric ions inserted into the oxygen octahedral interstices on TiO2 surface.
