The effect of copper and gold on the catalytic behavior of nickel/alumina catalysts in hydrogen-assisted dechlorination of 1,2-dichloroethane
The effect of copper and gold on the catalytic behavior of nickel/alumina catalysts in hydrogen-assisted dechlorination of 1,2-dichloroethane
复制标题
DOI：
10.1016/j.cattod.2010.08.019
复制
发表时间：
2011-07
期刊：
影响因子：
5.3
通讯作者：
W. Juszczyk;J. C. Colmenares;A. Śrębowata;Z. Karpiński
中科院分区：
文献类型：
--
作者：
W. Juszczyk;J. C. Colmenares;A. Śrębowata;Z. Karpiński
通过初湿共浸渍制备了两个系列的氧化铝负载的 Ni-Cu 和 Ni-Au 催化剂，并使用 -196°C 氮气吸附、X 射线衍射、氢气化学吸附和程序升温还原方法进行了表征。在还原的 Ni-Cu 和 Ni-Au 催化剂中发现的不同合金相的存在与这些系统的热力学预测的相相当一致，表明这两种合金系统都实现了合理的合金化程度。测试了Ni-Cu/Al2O3和Ni-Au/Al2O3催化剂在250和270℃下1,2-二氯乙烷加氢脱氯的反应。在 Ni/Al2O3 中添加 Cu 或 Au 会导致催化行为（尤其是产物选择性）发生重大变化（尽管有所不同）。在 250°C 下，铜的存在增强了镍形成氯乙烯的倾向（从~60% 到~85%），而金的添加则增加了乙烯的选择性（~20% 到~60%）。讨论了两种合金体系催化行为的差异。
Two series of alumina-supported Ni–Cu and Ni–Au catalysts were prepared by incipient wetness co-impregnation and characterized using nitrogen adsorption at −196°C, X-ray diffraction, hydrogen chemisorption, and temperature-programmed reduction methods. The presence of different alloy phases found in reduced Ni–Cu and Ni–Au catalysts was in fair agreement with the phases predicted by the thermodynamics of these systems suggesting that a reasonable extent of alloying was achieved for both alloy systems. The Ni–Cu/Al2O3and Ni–Au/Al2O3catalysts were tested in the reaction of hydrodechlorination of 1,2-dichloroethane at 250 and 270°C. Adding Cu or Au to Ni/Al2O3introduces substantial, although different, changes in the catalytic behavior, especially in the product selectivity. The presence of copper enhances the propensity of nickel towards vinyl chloride formation (from ∼60% to ∼85%), whereas addition of gold increases the selectivity to ethene (∼20% to ∼60%), at 250°C. Differences in catalytic behavior of both alloy systems are discussed.