摘要
用EPR,XRD,SEM,XPS,TPR,DSC等手段综合考察了铜铬氧化的催化剂结构与性能的联系.研究表明,油脂常压加氢时铜铬氧化物催化剂的活性组份是一种CuO和CuCr_2O_4的紧密结合物,其中Cu、Cr分别以Cu^(2+),Cr^(3+)形式存在.氢化反应后Cu^(2+)被还原成Cu^0,而Cr^(3+)不变.研究还表明,当焙烧气氛中氧较充分时会使催化剂中一部分Cr^(3+)氧化成Cr^(6+),从而导致催化剂活性下降.
The dependence of hydrogenation catayic activity on the structure of copper-chromium oxide catalysts was investigated by using EPR, XRD, XPS, SEM, TPR, DSC techniques. Our study showed that the active substance of catalysts in hydrogenation of soybean oil at atmosphere pressure looked like a combination of CuO and CuCr2O4, in which copper and chromium appeared as Cu2+ and Cr3+ respectively. The copper in catalysts was reduced from Cu2+to the Cu0while Cr3+ was not changed after hydrogenation reaction. The investigaion also showed that a part of Cr3+ in catalyst would be oxidized to be Cr6+ and the activity of catalysts hence decreased if there existed a great amount of oxygen in calcination atmosphere.
