燃料电池用Cu-Ce(La)Ox变换催化剂

对采用共沉淀法制备的Cu-Ce(La)O_x高温变换催化剂进行了研究，包括中和pH值、中和温度、焙烧温度和方式以及CuO、CeO₂和LaO_x含量对催化剂性能的影响。5%CuO-CeO₂-La(10%)O_x高温变换催化剂的最佳制备工艺条件为：pH＝11，中和温度54 ℃，400 ℃焙烧4 h。催化剂的最佳质量分数配比是：CuO 为20%，CeO₂ 为70%，LaO_x 为10%。XRD晶相分析表明，5%Cu-Ce-La(10%)O_x催化剂中除了主相CeO₂以外，还出现了Cu与La形成的钙钛矿型复合氧化物CuLaO₂，且CuLaO₂高度均匀地分散在主相CeO_x中；还原态中除了CeO₂、CuLaO₂外，还出现了Cu单质。因此，这类催化剂的活性中心不可能是简单的CuLaO₂或Cu，这使得催化剂无论氧化态还是还原态都具有基本相同的活性。催化剂的活性位形态结构尚需做进一步研究。

Cu-Ce(La)Ox water-gas shift catalysts for fuel cells

This paper studies Cu-Ce(La)O_x water gas shift catalysts prepared by co-precipitation, including the influence of neutralization pH, neutralization temperature, calcination temperature and content of CuO, CeO₂ and LaO_x. The optimum preparation condition for 5%CuO-CeO₂-La(10%)O_x catalyst is as follows：neutralization temperature 54 ℃，pH 11，calcining at 400 ℃ for 4 h. The optimum CuO∶CeO₂∶LaO_x is 20∶70∶10(atomic ratio). XRD results showed that perovskite CuLaO₂ were highly dispersed in the main phase CeO₂ in oxide-state 5%CuO-CeO₂-La(10%)O_x catalyst; there exist CeO₂ and CuLaO₂ and Cu phase in the reduced-state catalyst, which indicated that it is unlikely that CuLaO₂ or Cu are the only active sites for the water-gas shift reaction. The active sites for water gas shift reaction might have more complicated structures, which result in mostly identical activity for both oxide-state and reduced-state catalyst.