Abstract:

Catalytic hydrodeoxygenation of amides to amines is one of the most important approaches among all amine synthetic methods, and it is crucial to develop highly efficient hydrodeoxygenation catalysts. A series of Ru-VO _x /SiO₂ catalysts were prepared by the impregnation method. The physicochemical properties of the catalysts were characterized by using X-ray diffraction, Raman spectrum and so on. The hydrogenation of butyramide was used as a model reaction to evaluate the catalytic performance. The butyramide conversion and butylamine selectivity both varied with V and Ru atomic ratio in a curvilinear relationship characterized by an initial increase followed by a subsequent decrease, and the 0.5V-4Ru/SiO₂ catalyst (V and Ru atomic ratio=0.25) presented excellent catalytic performance at 150℃ under 5MPa H₂, giving a 90% conversion and 77% butylamine selectivity. The results suggested that the VO _x species, as the anchor, facilitated the dispersion of Ru nanoparticles and decorated on the Ru nanoparticle surface. Moreover, the electron interaction between Ru and V species promoted the reduction of V⁵⁺ species. The generated V⁴⁺ species, as the adsorption sites of amides, was benefit to the selective adsorption and activation of the carbonyl group of amides, thereby improving the activity and selectivity to amines in amide hydrodeoxygenation.

Key words: hydrogenation, selectivity, nanoparticles, catalyst, organic amine

摘要：

酰胺催化加氢脱氧制备有机胺是最具有吸引力的合成胺方法之一，开发高效加氢脱氧催化剂是实现酰胺加氢脱氧反应的关键。本文采用浸渍法制备了一系列Ru-VO _x /SiO₂催化剂，通过X射线衍射、Raman光谱等技术对催化剂的物化性质进行表征，以丁酰胺加氢作为模型反应来评价催化剂的催化性能。丁酰胺的转化率和正丁胺的选择性随催化剂的V/Ru原子比呈先增后降的曲线关系，0.5V-4Ru/SiO₂催化剂（V/Ru原子比为0.25）在150℃、5MPa H₂的条件下，表现出优异的催化性能，丁酰胺的转化率为90%，正丁胺的选择性为77%。结果显示，VO _x 物种作为锚点促进了Ru纳米颗粒的分散并修饰了Ru颗粒表面。此外，Ru和V之间的电子相互作用促进了V⁵⁺物种的还原。形成的V⁴⁺物种作为酰胺的吸附位点选择性地吸附和活化酰胺的羰基，从而提高了酰胺催化加氢脱氧反应的活性和选择性。

关键词: 加氢, 选择性, 纳米粒子, 催化剂, 有机胺