【摘要】 采用原位XRD、激光Raman光谱和TPR技术研究了不同温度焙烧的CuO/CeO2-Al2O3催化剂中CuO物种的存在形式及其高温固相反应。结果表明,300℃焙烧催化剂CuO以晶相和非晶相形式存在于CeO2-Al2O3的表层。600℃焙烧催化剂,表层CuO部分迁移到CeO2内层,并与载体Al2O3反应生成CuAl2O4。800℃焙烧催化剂,除了极少量CuO以晶相和非晶相形式存在于CeO2-Al2O3的表层外,大部分CuO迁移到CeO2内层,与载体反应生成CuAl2O4的量明显增加。900℃焙烧催化剂,所有的Cu物种都以CuAl2O4形式存在。表明高温焙烧有利于CuO向CeO2内层迁移及内层CuO与载体Al2O3反应生成CuAl2O4。更多还原

【Abstract】 CuO transference and thermal solid-solid interaction in CuO/CeO₂-Al₂O₃ catalysts prepared by an impregnation method were characterized by in-situ XRD,Raman spectroscopy and H₂-TPR techniques.For the catalyst calcined at 300 ℃,two kinds of CuO species coexist on the surface: highly dispersed and bulk CuO.Four kinds of CuO species present for the catalyst calcined at 600 ℃:（1） Highly dispersed CuO,（2） Bulk CuO on the surface,（3） Bulk CuO in the internal layer of CeO₂,and（4） CuAl₂O₄ formed from CuO-Al₂O₃ interaction.For the catalyst calcined at 800 ℃,besides very little highly dispersed and bulk CuO on the surface,CuO has transferred into the internal layer mostly and the amount of CuAl₂O₄ is increased.At 900 ℃,all of CuO diffuseds into the internal layer of CeO₂ and formes（CuAl₂O₄）.Experiment results show that the calcination temperature can promote transference of CuO from the surface into the internal layer and the CuO-Al₂O₃ interaction.更多还原