發(fā)布時(shí)間：2018-01-05 18:05

  本文關(guān)鍵詞：生物基多元醇高效氫解轉(zhuǎn)化的Ru基催化體系構(gòu)建及選擇性調(diào)控研究　出處：《上海應(yīng)用技術(shù)大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 山梨醇 Ru基催化劑 氫解 碳納米管 二元醇

【摘要】：二元醇是非常重要的聚酯類高分子單體,乙二醇、丙二醇等都可用于跟二酸反應(yīng),制得性能優(yōu)良的聚酯材料,因而需求量與產(chǎn)量巨大。我國(guó)二元醇年需求量已超過700萬噸,對(duì)外依存度高達(dá)86%,且其石油基生產(chǎn)路線難以持續(xù)。隨著國(guó)家經(jīng)濟(jì)社會(huì)的發(fā)展,對(duì)二元醇的需求量日益增加,發(fā)展以生物質(zhì)基糖醇等為原料的生物基二元醇生產(chǎn)新路線具有重要的現(xiàn)實(shí)意義。然而,在生物基碳水化合物的催化氫解反應(yīng)過程中,高溫和高氫壓的強(qiáng)反應(yīng)條件易導(dǎo)致目標(biāo)產(chǎn)物選擇性的下降。針對(duì)現(xiàn)行碳水化合物氫解制備二元醇過程中存在的反應(yīng)溫度高、產(chǎn)物選擇性差等問題,本研究力圖開發(fā)一種在溫和條件下即有較高催化活性和選擇性的碳水化合物選擇氫解催化反應(yīng)體系。據(jù)此,本文制備了不同載體負(fù)載的釕基催化劑,探索對(duì)該類催化劑活性中心和表面物化性質(zhì)進(jìn)行調(diào)變的方法,使得催化劑在保持對(duì)小分子裂解中間體較好加氫活性的同時(shí),降低其對(duì)單糖分子的催化加氫活性,并研究碳水化合物在其表面的吸附與選擇斷鍵路徑。取得的主要結(jié)果如下：(1)對(duì)于不同載體(分子篩、水滑石、類水滑石、碳納米管)的催化劑,采用浸漬法制備的碳納米管負(fù)載的Ru催化劑具有最高的加氫活性和最高的目標(biāo)醇選擇性。(2)對(duì)于以不同碳納米管(氨基化、羧基化、羥基化、石墨化和原始)為載體的催化劑,官能化后更利于活性金屬的負(fù)載。以山梨醇為底物,氫解反應(yīng)活性順序?yàn)镽u/ACNTs Ru/CNTs Ru/GCNTs Ru/CCNTs Ru/HCNTs.(3)以Ru/ACNTs為催化劑,添加不同堿助劑氫解山梨醇時(shí),反應(yīng)活性順序?yàn)長(zhǎng)iOH NaOH Ca(OH)2 CaO Mg(OH)2 Sr(OH)2 Ba(OH)2 KOH。綜合考慮反應(yīng)物轉(zhuǎn)化率、收率和選擇性,Ca(OH)2為最佳堿助劑。同時(shí)研究了堿助劑Ca(OH)2用量、催化劑用量、反應(yīng)時(shí)間、反應(yīng)溫度、初始?xì)錃鈮毫Φ纫蛩貙?duì)山梨醇?xì)浣夥磻?yīng)的影響。在200℃、初始?xì)錃鈮毫? MPa和反應(yīng)時(shí)間2 h,堿助劑Ca(OH)2使用量0.5g,催化劑用量0.3 g時(shí),山梨醇的轉(zhuǎn)化率可達(dá)93.9%,甘油、1，，2-丙二醇和乙二醇的總收率達(dá)55.2%,總選擇性達(dá)58.5%。
[Abstract]:Diol is a very important polyester macromolecule monomer, ethylene glycol, propylene glycol and so on can be used to react with diacid to produce polyester materials with good properties. The annual demand for diols in China has exceeded 7 million tons, the external dependence is as high as 86%, and its petroleum-based production route is not sustainable. With the development of national economy and society. The demand for diols is increasing day by day, so it is of great practical significance to develop a new route for the production of biological-based diols based on biomass based glycols. In the process of catalytic hydrogenation of biologically based carbohydrates. The high temperature and high hydrogen pressure could lead to the decrease of the selectivity of the target product. In view of the problems of high reaction temperature and poor product selectivity in the process of hydrogenolysis of carbohydrate to prepare diol. In this study, we tried to develop a carbohydrate selective hydrogenation catalytic system with high catalytic activity and selectivity under mild conditions. Based on this, ruthenium based catalysts supported on different supports were prepared. The method of modifying the active center and surface physicochemical properties of this kind of catalyst was explored, so that the catalyst could maintain better hydrogenation activity to small molecular pyrolysis intermediates and decrease its catalytic hydrogenation activity to monosaccharide molecules. The adsorption of carbohydrates on the surface and the selection of broken bond paths were studied. The main results are as follows: 1) Catalysts for different supports (molecular sieve, hydrotalcite, hydrotalcite, carbon nanotubes). The carbon nanotube supported Ru catalyst prepared by impregnation method has the highest hydrogenation activity and the highest target alcohol selectivity. 2) for different carbon nanotubes (amino, carboxylation, hydroxylation). The catalyst with graphitization and original) was more favorable to the loading of active metal after functionalization. Sorbitol was used as substrate. The order of hydrogenolysis activity is Ru/ACNTs Ru/CNTs Ru/GCNTs Ru/CCNTs Rur. HCNTs. 3) using Ru/ACNTs as catalyst. When different alkali additives were added in the hydrogenolysis of sorbitol. The order of reaction activity was LiOH NaOH Ca(OH)2 CaO Mg(OH)2 Sr(OH)2 Ba(OH)2 KOH.The conversion of reactants was taken into account. The yield and selectivity of CaOH _ (2) were used as the best base auxiliaries. The amount of Ca(OH)2, the amount of catalyst, the reaction time and the reaction temperature were also studied. The effect of initial hydrogen pressure on the hydrogenolysis of sorbitol was investigated. At 200 鈩

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