【摘要】 本文研究了铈助剂在低碳混合醇合成中的作用。发现,在Cu-Zn-Al-K催化剂中,以铈取代部分铝,可抑制钾的副作用,延长催化剂的使用寿命,提高高级醇的选择性。同时还发现含铈催化剂表面有纤维网络存在;反应后催化剂中CeO₂特征衍射峰消失,有新的未辨明的物相生成。认为:由大量细小的纤维组成的纤维网络可以对催化剂的结构起稳定作用,有利于热的传递;在反应过程中由于CeO₂部分还原,促进了铈与铜之间的重新分散,加强了二者间的相互作用,抑制铜晶烧结,从而提高了催化剂的热稳定性。另外,铈的存在,可以使钾稳定分散在催化剂表面,有利于高级醇的生成。更多还原

【Abstract】 The role of cerium dioxide modifier in Cu-Zn-Al-K catalys for low alcohols synthesis have been investigated, Cerium can depress the side effect of potassium on cataiyst and improve the lifetime of the catalyst. Fibrous network was found on the surface, of catalyst with Ce. After reaction the characteristic diffraction peaks of CeO₂ disappeared and new unknown phases appeared in the X-ray powder diffraction pattern of the catalyst. It is considered that the network composed of a large amount of small fibres stabilizes the structure of the catalyst and therefore promotes heat transfer on the surface of catalyst. During reaction period, the partial reduction of CeO₂ stimulates the redispersion between Ce and Cu, strengthens the interreaction of Ce and Cu and depresses the sintering of the Ce and Cu crystallite, thus promotes the heat stability of the catalyst. On the other hand, in the presense of CeO₂, potassium is localized on the surface of catalyst and therefore the selectivity of higher alcohols synthesis is increased.更多还原