甲烷二氧化碳重整用Ni/AC催化剂的阈值效应研究

摘要

In order to research the threshold effect of supported nickel catalyst for methane-carbon dioxide reforming reaction, the nickel catalysts supported on activated carbon were analyzed by nitrogen adsorption-desorption (BET) and X-ray diffraction (XRD). The effects of the solvents of dipping solution and nickel loading on the surface structure, nickel dispersion degree and dispersion threshold were studied. The results showed that when acetone was used as the solvent, the nickel dispersion degree was higher than used purity water. The effective area and dispersion threshold of active components also were increased. The calculated value with the close-packed model suggested that Ni preferred to disperse as a sub monolayer, but not a close-packed monolayer. The results of CH4-CO2 reforming experiments indicated that catalytic activity was higher by using acetone as the solvent than purity water. It showed that the threshold effect of the supported Ni/AC catalysts existed in the CH4-CO2reforming.%为研究活性炭负载Ni（Ni/AC）基催化剂在甲烷二氧化碳重整反应中的阈值效应，采用N2吸附（BET）和X射线衍射（XRD）测试技术对活性炭负载Ni（Ni/AC）基催化剂进行分析，分别探讨了浸渍溶剂和负载量对催化剂表面结构、Ni分散状态和分散阈值的影响。结果表明，采用丙酮作为溶剂制备的催化剂比纯水在活性炭载体表面更有利镍的分散，提高了活性组分有效面积，并具有更高的分散阈值。对比密置单层排列模型计算值认为Ni在AC表面呈非密置单层或亚单层分散。Ni/AC催化重整甲烷二氧化碳实验结果显示，丙酮作为浸渍溶剂比纯水制备的催化剂表现出更好的催化活性，负载型Ni/AC催化剂在甲烷二氧化碳重整反应中存在显著的阈值效应。