Nanostructured LaCo1-xZnxO3 (x = 0, 0.05, 0.1, 0.2, 0.3 and 0.5) perovskites were synthesized by a one-step citric acid-complexing method for hydrogen production by the steam reforming of ethanol. For comparison, 8％ CoO/ZnO and 8％ CoO/La2O3 were prepared by impregnation and evaluated. The catalyst samples were characterized by X-ray diffraction, temperature-programmed reduction, and X-ray photoelectron spectroscopy. The results indicated that zinc did not favor the formation of the LaCo1-xZnxO3 perovskite and the structures of the substituted samples were less weakening than that of LaCoO3. Some segregation was observed for x ＞ 0.1. The reactivity of the studied samples was sensitive to the zinc content and lower substitution values were found to be better. An unexpected phase (Co3O4) appeared in the fresh LaCo0.9Zn0.1O3 sample. The presence of the Co3O4 phase increased the reactivity toward hydrogen production by the steam reforming of ethanol. The presence of La2O2CO3 is responsible for the low carbon deposition and the CH4 selectivity in the aged samples.%利用一步柠檬酸络合法合成了钙钛矿LaCo1-xZnxO3(x=0,0.05,0.1,0.2,0.3,0.5),并将其用于乙醇水蒸气重整反应.利用X射线衍射、程序升温还原和X射线光电子能谱对催化剂进行了表征.结果表明,Zn的加入不利于形成LaCo1-xZnxO3钙钛矿结构,当x≥0.1时产生了一些分离相.新鲜LaCo0.9Zn0.1O3催化剂中意外发现存在Co3O4相,这有利于催化剂反应性能的提高.反应后的催化剂结构发生变化,形成了La2O2CO3,而该物质有利于积炭的消除和甲烷的重整.
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