双金属氧化物负载钌催化5-羟甲基糠醛加氢性能的研究

发布时间：2018-04-27 05:37

本文选题：选择性加氢 + 双金属氧化物　；参考：《山东农业大学》2017年硕士论文

【摘要】：5-羟甲基糠醛作为最具潜力的生物质基平台分子之一,是联系生物质资源与石油基工业的桥梁和关键物质,它可以衍生出许多呋喃类化工产品通过催化加氢、氧化脱氢、酯化、卤化等化学反应。2.5-二甲基呋喃(DMF)是一种可比拟汽油的新型液体生物燃料,能解决乙醇作为生物质燃料的诸多不足,可由5-羟甲基糠醛通过催化加氢制得,因此开发一种高效转化为DMF的催化剂是当务之急。而寻找合适的载体是制备高选择性催化剂的最有效的方法。双金属氧化物由于其酸碱度,稳定性等特性在多相催化领域受到广泛的关注。本文以金属氧化物为载体,以Ru金属为活性位点组装催化剂,探究载体对Ru金属催化5-羟甲基糠醛加氢性能的促进作用。详细内容如下:1.CoFe类水滑石氧化物负载Ru对5-羟甲基糠醛加氢性能的研究本实验采用还原-沉淀法,将贵金属Ru负载到MM-LDO(M=Co,Ni,Fe)表面,得到不同催化剂,并探究其对5-羟甲基糠醛的催化加氢性能。实验表明Ru/CoFe-LDO表现很高的催化活性。以Ru/CoFe-LDO为最优催化剂,采用XRD、SEM、TEM、FT-IR、TGA、XPS等表征载体及催化剂的结构特征,探究反应温度、反应时间、反应压力、催化剂的量及煅烧温度对催化性能的影响,并提出可能的反应途径。由于CoFe-LDO与贵金属Ru的协同作用,进一步促进HMF转化为DMF。2.Fe-Al金属氧化物气凝胶负载贵金属Ru对5-羟甲基糠醛选择性加氢性能的研究本实验采用恒pH-共沉淀法制备M-Al(M=Fe,Ni,Co,Cr,Mn)氢氧化物气凝胶,通过超临界乙醇干燥并煅烧得M-Al金属氧化物气凝胶。以M-Al金属氧化物气凝胶为载体的Ru基催化剂用于HMF的选择性加氢反应,实验表明Ru/Fe-A表现出最好的活性及对DMF的选择性。与类水滑石氧化物相比,金属氧化物气凝胶载体具有低密度,高比表面积,大孔和高热稳定等优点,具有较高的活性中心分散性和较好的传质性能。实验表明,Fe-A为载体表现出非常好的催化活性和对DMF的选择性。通过重复性实验对催化剂进行稳定性测试,表明Ru/Fe-A具有很好的催化性能和稳定性。3.ZIF模板化金属氧化物负载贵金属Ru对5-羟甲基糠醛选择性加氢性能的研究本实验采用ZIF为模板制备中空结构的ZnCo4O5复合氧化物,以其为载体采用传统的浸渍-还原-沉淀法制备了 Ru基催化剂,并以此作为HMF选择性加氢的催化剂。与类水滑石氧化物和金属氧化物气凝胶相比,中空结构的ZnCo4O5复合氧化物载体具有十二面体结构,高比表面积,高热稳定等优点,具有较高的活性中心分散性和较好的传质性能,其中Ru的负载量为3%,DMF选择性能达到95.3%,表明Ru/ZnCo4O5具有更好的催化活性。通过重复性实验对催化剂进行稳定性测试,表明Ru/Fe-A具有很好的催化性能和稳定性。
[Abstract]:As one of the most promising biomass-based platform molecules, 5-hydroxymethyl furfural is a bridge and key substance between biomass resources and petroleum-based industry. It can derive many furan chemical products through catalytic hydrogenation, oxidative dehydrogenation and esterification. Halogenation and other chemical reactions .2.5- dimethylfuran (DMF) is a new liquid biofuel comparable to gasoline, which can solve many shortcomings of ethanol as biomass fuel and can be prepared by catalytic hydrogenation of 5-hydroxymethyl furfural. Therefore, it is urgent to develop a catalyst for high-efficiency conversion to DMF. Finding suitable support is the most effective method to prepare high selectivity catalyst. Bimetallic oxides have attracted much attention in heterogeneous catalysis due to their pH and stability. In this paper, metal oxide was used as the carrier and Ru metal as the active site to assemble the catalyst to explore the effect of the support on the hydrogenation of 5-hydroxymethyl furfural catalyzed by Ru. The hydrogenation properties of 5-hydroxymethylfurfural supported on Cofe hydrotalcite oxides were studied. In this experiment, the noble metal Ru was loaded on the surface of MM-LDO (MM-LDO) MCoCoNiFe) by reduction-precipitation method, and different catalysts were obtained. The catalytic hydrogenation of 5-hydroxymethyl furfural was investigated. The experimental results show that Ru/CoFe-LDO exhibits high catalytic activity. Using Ru/CoFe-LDO as the optimal catalyst, the structure characteristics of the support and catalyst were characterized by XRDX SEMMET TGA XPS. The effects of reaction temperature, reaction time, reaction pressure, amount of catalyst and calcination temperature on the catalytic performance were investigated, and the possible reaction paths were proposed. Due to the synergistic effect of CoFe-LDO and noble metal Ru, the conversion of HMF to DMF.2.Fe-Al metal oxide aerogel loaded with noble metal Ru for selective hydrogenation of 5-hydroxymethyl furfural was further promoted. M-Al metal oxide aerogels were prepared by drying and calcining with supercritical ethanol. Ru based catalyst supported on M-Al metal oxide aerogel was used for selective hydrogenation of HMF. The results showed that Ru/Fe-A exhibited the best activity and selectivity to DMF. Compared with hydrotalcite-like oxides, metal oxide aerogel carriers have the advantages of low density, high specific surface area, large pore size and high thermal stability. The experimental results show that Fe-A as the carrier has very good catalytic activity and selectivity to DMF. The stability of the catalyst was tested by repeated experiments. The results showed that Ru/Fe-A had good catalytic performance and stability. 3. The selective hydrogenation of 5-hydroxymethylfurfural with metal oxides supported on Ru was studied. In this experiment, hollow ZnCo4O5 composite oxides were prepared by using ZIF as template. Ru based catalysts were prepared by traditional impregnation-reduction-precipitation method and used as catalysts for selective hydrogenation of HMF. Compared with hydrotalcite-like oxides and metal oxide aerogels, hollow ZnCo4O5 composite oxide carriers have the advantages of dodecahedron structure, high specific surface area, high thermal stability, high dispersion of active centers and better mass transfer properties. The selectivity of Ru to DMF is 95.3, which indicates that Ru/ZnCo4O5 has better catalytic activity. The stability of the catalyst was tested by repeated experiments. The results show that Ru/Fe-A has good catalytic performance and stability.
【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36

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