Ruthenium-oxo species with high oxidation performance supported on nano-scale particles prepared by the solvothermal reaction

在这项工作中，我们旨在设计具有Ru=O基团的Ru物种，这种Ru物种高度分散在溶剂热反应制备的金属氧化物载体上。这种Ru物种有望对氧化反应具有特殊的高活性。首先，聘请了CEO_2作为后盾。金属Ce在2-甲氧基乙醇中的溶剂热反应生成了平均粒径为2 nm的超细CeO_2胶体粒子。将得到的CeO2胶体溶液用不同的凝固剂进行凝聚，制得CeO2粉末。不同的混凝剂(NaOH、NH_4OH、Na_2CO_3、(NH_4)_2CO_3、NaHCO_3)的孔结构不同。用(NH4)2CO3和NaHCO3制备的CeO2粉末具有大孔和中孔结构，而用NaOH和NH4OH制备的CeO2粉末具有较多的微孔结构。Ru能以较好的分散状态负载在CeO_2上，但不能负载在CeO_2的微孔中，因此前者比…具有更高的苯甲醇氧化活性用常规沉淀法从AQ开始制备CeO_2样品，并对样品的性质进行了表征。比较了Ce(NO3)3与溶剂热法合成CeO2胶体溶液制备的Ce(NO3)3的异同。溶剂热样品易于还原和再氧化，其表面活化氧含量高于沉淀法样品。结果表明，溶剂热法制备的CeO2上负载的Ru的活性远大于沉淀法制备的CeO2上的Ru，表明了溶剂热法制备高性能超细金属氧化物粒子的优越性。获得Ru物种的目标载体为：ZrO_2、TbO_2和Pr_6O_(11)。然而，它们都没有成功地培育出这种汝种。本研究的结论是，Ru与CeO_2的结合是产生Ru=O键的分散细小的Ru物种的唯一且独特的体系。作者期待该催化剂在各种有机反应中具有很高的应用潜力。较少

In this work, we aimed at designing Ru species with Ru=O group which is highly dispersed on metal oxide supports prepared by the solvothermal reaction. This Ru species is expected to have peculiar and high activity for oxidation reactions. First, CeO_2 was employed as a support. The solvothermal reaction of Ce metal in 2-methoxy ethanol produced ultra fine CeO_2 colloidal particles whose average diameter was 2nm. The obtained CeO_2 colloidal solution was coagulated by various coagulants to produce CeO_2 powders. Their pore structures varied with the kinds of coagulants (NaOH, NH_4OH, Na_2CO_3, (NH_4)_2CO_3, NaHCO_3). The CeO_2 powders produced by using (NH_4)_2CO_3 and NaHCO_3 had macro and meso pores while those obtained with NaOH and NH_4OH had much micro pores. Ruthenium could be supported on the former CeO_2 in a well dispersed state but could not be supported in the micro-pore of the latter; thus, the former catalysts had higher activity in the oxidation of benzyl alcohol than the … More latter.The natures of the CeO_2 sample prepared by an ordinary precipitation method starting from aq. Ce(NO_3)_3 and the one prepared by starting from CeO_2 colloidal solution synthesized by the solvothermal method were compared. The solvothermal sample could be easily reduced and re-oxidized; it had larger amount of surface mobile oxygen than the precipitation sample. Consequently, the activity of the Ru supported on the solvothermal CeO_2 was much larger than that on the CeO_2 prepared by the precipitation method; indicating the excellence of the solvothermal method to prepare high performance ultra fine metal oxide particles.Various other supports were examined to obtain Ru species with Ru=O bond. The target supports to obtain the Ru species were ZrO_2, TbO_2, and Pr_6O_<11>. However, none of them were successful to produce this kind of Ru species. Conclusion of the present research is that the combination of Ru with CeO_2 is the sole and unique system to produce the finely dispersed Ru species with the Ru=O bond. The author expects the high potential of this catalyst to be used in various organic reactions. Less