Synthesis of Secondary Monoalcohols from Terminal Vicinal Alcohols over Silica-Supported Rhenium-Modified Ruthenium Catalyst
Synthesis of Secondary Monoalcohols from Terminal Vicinal Alcohols over Silica-Supported Rhenium-Modified Ruthenium Catalyst
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二氧化硅负载铼改性钌催化剂上端邻醇合成仲单醇
DOI：
10.1021/acssuschemeng.1c07023
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Tomishige Keiichi
中科院分区：
文献类型：
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作者：
Liu Ben;Sekine Naoyuki;Nakagawa Yoshinao;Tamura Masazumi;Yabushita Mizuho;Tomishige Keiichi
以1，2-丙二醇（1，2-PrD）为模型底物，采用Ru基催化剂，研究了1，2-链烷醇C-O氢解选择性合成仲醇的反应。Ru/SiO2催化剂经ReOx改性后，催化活性得到了显著提高。在Ru-ReOx/SiO2（Re/Ru = 0.5）催化剂上，1，2-PrD的氢解反应首先生成2-丙醇（2-PrOH）和1-丙醇（1-PrOH），选择性相近沿着生成≤ C2化合物，然后1-PrOH优先转化为丙烷，结果在较长的反应时间内，只有2-PrOH保留在液相中，产率为23%。该催化剂可重复使用至少两次。H2-TPR、XRD、TEM-EDX、XANES和EXAFS等表征表明，Ru-ReOx/SiO2催化剂中的Ru物种在反应条件下被完全还原，而部分Re物种也被还原为部分还原的单体物种（Reδ+Ox），而没有Re-Re直接键位于Ru金属颗粒表面。这种ReOx改性的Ru金属表面可能作为活性位点。过量的Re物质被还原成大的Re金属颗粒;然而，这些Re金属颗粒不参与催化。
The selective synthesis of secondary alcohols from 1,2-alkanediol by C–O hydrogenolysis, which has been less investigated than the synthesis of primary alcohols, was investigated with Ru-based catalysts and 1,2-propanediol (1,2-PrD) as a model substrate. The modification of Ru/SiO2with ReOxachieved significant improvement of activity. The hydrogenolysis of 1,2-PrD over Ru–ReOx/SiO2(Re/Ru = 0.5) initially formed both 2-propanol (2-PrOH) and 1-propanol (1-PrOH) with similar selectivity along with the formation of ≤ C2 compounds, and then 1-PrOH was preferably converted to propane; as a result, only 2-PrOH remained in the liquid phase with 23% yield at longer reaction time. This catalyst was reusable at least twice. The characterization with H2-TPR, XRD, TEM-EDX, XANES, and EXAFS showed that the Ru species in the Ru–ReOx/SiO2catalysts were completely reduced in the reaction conditions, while a part of Re species were also reduced to partially reduced monomeric species (Reδ+Ox) without Re–Re direct bond located on the surface of Ru metal particles. This ReOx-modified Ru metal surface probably works as the active sites. The excess Re species was reduced to large Re metal particles; however, these Re metal particles are not involved in the catalysis.