摘要
为获得高分散的Ru负载催化剂，采用乙二醇液相化学还原沉积法制备Ru／CNTs，TEM、XRD、H2-TPD表征，结果表明，乙二醇液相还原法可以制备金属粒径小（2—4nm）而均匀的高分散度的钌修饰CNTs，其表面存在较高稳态浓度吸附氢。以氨分解制氢作探针反应，实验结果表明，在相同反应条件下，经乙二醇油浴液相还原沉积制备的Ru／CNTs催化剂上氨转化率约为浸渍法制得相应催化剂上的1．6倍，同时发现钌微晶粒径在3—4nm范围的Ru／CNTs对氨分解制氢的催化性能最佳，钌微晶粒径≤2nm时氨分解转化率明显下降。
With CNTs as substrate, a series of metallic Ru/CNTs were prepared by using glycol reduction-deposition method for gaining Ru-loading catalyst dispersed highly. TEM observations, XRD and H2-TPD measurements of the produced materials showed that metal Ru nanoparticles were quite uniform in shape and size and well dispersed on the CNTs surface and the Ru/CNTs could adsorb considerably greater amount of hydrogen when using glycol reduction - deposition method, especially by micromaveassisted heating polyol process. The observed NH3-decomposition conversion over Ru/CNTs catalyst prepared through ethylene glycol reduction-deposition was about 1.6 times as high as that of Ru/ CNTs catalyst prepared by conventional incipient wetness method under the same reaction condition. The results of the present work demonstrated that NH3 decomposition over the Ru/CNTs catalyst using glycol reduction- deposition method with the Rux^0-crystallite size at 3-4 nm displayed the highest reaction activity; while Ruz^0 particle size came down to 2 nm and below, the conversion of NH3 decomposition was markedly dropped.
基金
国家重点基础研究发展规划“973”项目（2005CB221400）,国家自然科学基金项目（20473063和20590364）
关键词
钌/碳纳米管
液相化学还原沉积
氨分解制氢
Ru/carbon nanotubes
glycol reduction-deposition method
NH3 decomposition
