生物质甘油氢解Ru基双金属催化剂的构效关系研究

Glycerol is a green chemical which can be derived from biomass. In recent years, the rapid development of biodiesel production formed large quantities of glycerol as a by-product. The catalytic hydrogenolysis of glycerol is an environment-friendly reaction that can obtain important organic chemicals like propanediol; it is also one of the most attractive subjects in green chemistry. To develop feasible and efficient catalysts is the key point to achieve the hydrogenolysis of glycerol to propanediol. In this reaction, it has been proved that the changes of the catalyst structure have an effect on its performance. However, the exact structure-performance relationship is still undefined and the influence law is indistinct, resulting in blindness of catalysts development. In our earlier work, we have demonstrated that the Ru-based catalysts show high activity for the hydrogenolysis of glycerol; the selectivity to propanediol can be markedly improved when introducing a suitable second metal. Based on this issue, the research emphasis of this study is focused on the structure-performance relationship of the glycerol hydrogenolysis catalysts. The Ru-based bimetallic catalysts with different structure characteristics are prepared by appropriate techniques, and used in the hydrogenolysis of glycerol. The catalysts are characterized by SEM, TEM, XRD, TPR and gas adsorption. The structure-performance relationship of the glycerol hydrogenolysis catalysts can be made clear by comprehensive analysis of the catalysts characterization results and the catalytic performance data; the influence law of the catalysts structure on the catalytic performance can be revealed. This study will provide theoretical foundation for the research of catalysts in the hydrogenolysis of glycerol to propanediol.

甘油是一种可来源于生物质的绿色化学品。研究甘油催化氢解合成丙二醇是当前绿色化学领域的重要课题之一。实现上述转化的前提和关键是获得适宜高效的氢解催化剂。在甘油氢解反应中，催化剂的结构变化会影响其催化性能已得到初步证实，但具体的构效关系尚未明确，影响规律还不清楚，导致催化剂的研制带有盲目性。申请者前期研究发现Ru基催化剂在甘油氢解反应中具备很高活性，当引入适当的第二金属组分时还可显著提高丙二醇的选择性。基于此，本项目拟制备一系列具有不同结构特点的Ru基双金属催化剂并将其用于甘油的氢解反应，重点研究该体系中催化剂的结构变化对其催化性能的影响规律。利用SEM、TEM、XRD、TPR和气体吸附等多种现代分析技术对催化剂结构进行表征；通过综合分析催化剂的结构表征结果和催化性能数据，揭示催化剂结构对催化性能的影响规律，明确催化剂构效关系。研究结果将为甘油氢解合成丙二醇催化剂的研制奠定理论基础。

近年来，生物柴油产业化过程中副产了大量的甘油，导致甘油的需求严重过剩。以甘油为原料，通过催化氢解可以得到1,2–丙二醇等重要化学品，这一转化甘油的路径是增长生物柴油产业链、提高其经济效益的有效途径。已有报道初步证实了催化剂的结构变化会影响其催化性能，但具体的构效关系尚未明确，导致催化剂的研制带有盲目性，限制了该过程的实际应用。本项目以具备高活性的Ru作为主要活性组分之一，制备了一系列具有不同结构特点的Ru基双金属催化剂，主要包括Ru-Cu/Fe3O4-TiO2、Ru-Ni/Fe3O4-ZrO2和Ru-Co/ZrO2等，同时还制备了Ce改良的Ru基催化剂；研制出的Ru基催化剂在甘油氢解反应中表现出高转化率、良好的稳定性和1, 2-丙二醇选择性。第二组份如Cu、Ni、Co或Ce物种的加入，可以有效地提高催化剂对于1, 2-丙二醇的选择性；利用多种分析手段对催化剂结构进行了全面表征，评价了所制备的催化剂在甘油氢解反应中的性能，考察了各种变量因素对催化剂性能的影响；结合催化剂的结构表征和催化性能结果，揭示并明确了催化剂在甘油氢解反应中的构效关系。另外，针对不同的催化体系，分别提出了不同催化剂上甘油氢解反应的具体过程。本课题的研究为甘油氢解合成丙二醇催化剂的研制奠定理论基础，并为该催化工艺的工业化应用提供了技术参考。