CuO/Al_2O_3催化剂高温固相反应的原位XRD和Raman研究

In-situ XRD and Raman Spectroscopic Study on the Solid State Reaction of CuO/Al_2O_3 Catalysts at High Temperature

采用原位 XRD 和激光 Raman 光谱等技术对 CuO/Al_2O_3系列催化剂高温下的表面组成和体相结构的变化进行研究，结果表明，随着焙烧温度升高，CuO 首先与载体 Al_2O_3发生固相反应生成 CuAl_2O_4．CuAl_2O_4层能阻止外层 CuO 进一步向载体 Al_2O_3扩散，从而使部分 CuO 稳定在 CuO/Al_2O_3催化剂的表层。

A series of CuO/Al2O3 catalysts were prepared by impregnation method with different loadings, and calcined temperatures. The phase evolution of the surface region and the bulk on the CuO/Al2O3 catalysts was characterized by high-temperature in-situ XRD and Raman techniques. The experimental results show that CuAl2O4 phase formed as a result of a solid-solid interaction between CuO and Al2O3 when the calcination temperature reaches to 800 degreesC, and the amount of CuAl2O4 increases at high temperature, which brings on the CuO in the surface region becomes more difficult to extend into the bulk, then the CuO can be stabilized on the surface region even after calcination at 900 degreesC.