Marked capability for hydrogen occlusion of hollow silica nanospheres containing group 8–10 metal clusters
Marked capability for hydrogen occlusion of hollow silica nanospheres containing group 8–10 metal clusters
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DOI：
10.1016/j.cattod.2007.12.077
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发表时间：
2008-03
期刊：
影响因子：
5.3
通讯作者：
T. Miyao;K. Minoshima;Y. Kurokawa;K. Shinohara;Weihua Shen;S. Naito
中科院分区：
文献类型：
--
作者：
T. Miyao;K. Minoshima;Y. Kurokawa;K. Shinohara;Weihua Shen;S. Naito
通过将相应的金属氨络合物增溶到NP-6/环己烷反胶束体系中，合成了含有Rh、Ir和Ru等多种贵金属簇的空心二氧化硅纳米球。金属氨络合物在反胶束中发生缩合和成核，所得氨络合物纳米晶体充当在二氧化硅球中形成中空腔的结构导向剂。纳米空心球在高达 1073K 的热处理下保持稳定。通过这种方法，也很容易合成双金属纳米粒子，即Rh-Co-SiO2和Ir-Co-SiO2，并且空心中含有的两种金属元素在热处理后可以合金化。 Ir-和Rh-SiO2纳米空心体表现出过量的氢吸收。特别是，在 Ir-SiO2 样品上，在室温下 200Torr 的氢气下，H/Ir 比达到 3.3。在较高压力下，2.6MPa时H/M值达到11.6。
Hollow silica nanospheres containing various precious metal clusters such as Rh, Ir and Ru were synthesized by solubilizing corresponding metal ammine complexes into NP-6/cyclohexane reversed micelle system. The condensation and nucleation of the metal ammine complex in the reversed micelles took place and the resulting nanocrystals of the ammine complexes acted as a structure-directing agent for the formation of hollow cavity in silica spheres. The nano-hollow spheres were stable for thermal treatment up to 1073K. By this method, bimetallic nanoparticles, i.e. Rh–Co–SiO2and Ir–Co–SiO2, were also easily synthesized and both metal elements containing in the hollows may be alloyed after thermal treatment. The Ir– and Rh–SiO2nano-hollows exhibited excess hydrogen uptake. In particular, over Ir–SiO2sample, the H/Ir ratios reached 3.3 under 200Torr of hydrogen at room temperature. At higher pressure, the H/M value reached 11.6 at 2.6MPa.