The hydrodeoxygenation of a model compound, ethyl stearate, of biomass-derived resources into long chain alkanes was investigated with Re-modified Ru/TiO₂ catalysts. A monometallic Ru(1)/TiO₂ catalyst, in which Ru was loaded in 1 wt%, gave a selectivity of >95% to the long chain alkanes of n-octadecane and n-heptadecane at almost 100% conversion at 220 °C, while another monometallic Re(10)/TiO₂ catalyst was less active in spite of its higher metal loading (10 wt%). It is interesting that the addition of less active Re species to Ru(1)/TiO₂ not only enhanced the rate of hydrodeoxygenation and increased the ratio of n-octadecane/n-heptadecane, while the high total selectivity towards alkanes remained unchanged. The alkane ratio depended on the content of Re added, increasing significantly from 0.5 for Ru(1)/TiO₂ to 3.2 for Ru(1)Re(10)/TiO₂. The impacts of Re addition on the catalytic performance of Ru/TiO₂ were discussed on the basis of physicochemical properties characterized for Re-modified and unmodified Ru/TiO₂ catalysts. It is suggested that the improved hydrodeoxygenation activity of Re-modified catalysts depends on the presence of Lewis acid sites, and the weak acid sites are important for determining catalytic selectivity. In addition, reaction pathways in the hydrodeoxygenation of ethyl stearate to n-octadecane and n-heptadecane were examined by control reactions with possible intermediates such as 1-octadecanol and stearic acid. The Re-modified Ru/TiO₂ catalysts were shown to be recyclable during repeated runs when the same mole ratio of catalyst to substrate was used.

中文翻译：

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Re-促进的Ru / TiO2催化剂上的硬脂酸乙酯加氢脱氧：通过添加Re来提高速率和选择性

用重改性的Ru / TiO ₂催化剂研究了生物质来源的模型化合物硬脂酸乙酯加氢脱氧成长链烷烃。Ru以1 wt％负载的Ru（1）/ TiO ₂单金属催化剂在220°C时几乎100％的转化率对正十八烷和正十七烷的长链烷烃的选择性> 95％，尽管另一种单金属Re（10）/ TiO ₂催化剂尽管具有较高的金属负载量（10 wt％），但活性较低。有趣的是，向Ru（1）/ TiO _2中添加活性较低的Re物种不仅提高了加氢脱氧的速率，而且提高了n-十八烷/ n的比例。-十七烷，而对烷烃的高总选择性保持不变。烷烃比例取决于所添加的Re含量，从Ru（1）/ TiO _2的0.5显着增加到Ru（1）Re（10）/ TiO _2的3.2。在表征重改性和未改性Ru / TiO ₂催化剂的物理化学性质的基础上，讨论了稀土元素添加对Ru / TiO ₂催化性能的影响。建议改质催化剂的加氢脱氧活性的提高取决于路易斯酸位点的存在，而弱酸位点对于确定催化选择性很重要。此外，硬脂酸乙酯加氢脱氧为正十八烷和通过与可能的中间体（例如1-十八烷醇和硬脂酸）的对照反应检查了正十七烷。当使用相同的催化剂与底物的摩尔比时，在重复的运行过程中，再改性的Ru / TiO ₂催化剂被证明是可回收的。