Ni-Cu/CeO2催化剂上乙醇水蒸气重整反应

 研究了Ni-Cu/CeO2催化剂在乙醇水蒸气重整反应中的催化性能. 以具有高比表面积的CeO2为载体,用沉积沉淀法制备了一系列不同担载量的Ni, Cu双组分催化剂,采用X射线衍射、程序升温还原和透射电子显微镜对催化剂的晶相组成、还原性能和形貌进行了表征. 结果表明, CuO, NiO和CeO2的相互作用明显改善了NiO的分散. 适量CuO的加入使NiO分散度增大,颗粒明显变小,从而使催化剂具有更好的催化性能,但过多CuO的加入反而降低了催化剂的活性. Ni和Cu的催化性能差异较大, Ni具有优异的断裂C-C键性能,在低温下即可实现乙醇的完全转化,而在高温区则具有很好的甲烷重整性能,可获得很高的氢气产率; Cu在低温区倾向于使乙醇脱氢生成乙醛以及进一步脱羰基生成丙酮,在高温区也具有一定的乙醇裂解性能.

Steam Reforming of Ethanol over Ni-Cu/CeO2 Catalyst

The catalytic performance of Ni-Cu/CeO_2 catalyst for hydrogen production from ethanol steam reforming was investigated with respect to the roles of nickel and copper. The structure and surface characteristics of the catalyst were measured by temperature-programmed reduction, X-ray diffraction, and transmission electron microscopy. It was revealed that the interactions among Cu, Ni, and CeO_2 greatly improved the dispersion of Ni particles and consequently enhanced the catalytic activity, but too much copper decreased the activity of the catalyst. Ni was more effective in the cleavage of C-C and C-H bonds than Cu, and thus ethanol was entirely converted even at much lower temperatures. Additionally, Ni also exhibited excellent methane reforming capability at higher temperatures. Cu favored the dehydrogenation of ethanol to acetaldehyde and water-gas shift reaction at low temperatures, and only showed limited ability for ethanol decomposition at high temperatures.