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  本文關(guān)鍵詞： 乙二醇 檸檬酸 釔 甲烷重整 合成氣 鎳基催化劑　出處：《華南理工大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：急速的工業(yè)發(fā)展和人口增長導(dǎo)致的石油過度消耗,引起了世界對全球變暖和有限石油儲量消耗的關(guān)注。甲烷重整反應(yīng)可以將甲烷轉(zhuǎn)化為高附加值的合成氣(H2和CO),然后合成氣可以轉(zhuǎn)變成各種化工產(chǎn)品,如甲醇、二甲醚和含氧化合物等。本論文從鎳基催化劑的修飾和合成策略兩個方面進行詳細研究。合成以有機溶劑修飾的Ni基催化劑,并采用不同浸漬策略(分步浸漬和共浸漬)分別合成了二氧化硅和氧化鋁負載的摻釔鎳基催化劑,詳細研究鎳基體系催化劑在甲烷重整反應(yīng)中的催化性能,通過X-射線粉末衍射(XRD)、氮氣吸附-脫附曲線、程序升溫還原(TPR)、透射電子顯微鏡(TEM)、傅里葉變換紅外光譜(FT-IR)和熱重分析技術(shù)(TG)等表征手段對催化劑結(jié)構(gòu)進行詳細解析,系統(tǒng)說明了有機助劑在提高催化性能中的關(guān)鍵作用;探討含釔催化劑的合成策略(共浸漬法和分步浸漬法)對不同載體(Al2O3和Si O2)催化劑催化性能的影響,揭示了浸漬方法對于不同載體的影響,研究結(jié)果進一步闡明了對于鎳基催化劑的助劑添加和載體修飾在催化劑結(jié)構(gòu)和催化性能方面的優(yōu)越性。本論文的研究成果對于完善現(xiàn)有鎳基重整催化體系具有重要的指導(dǎo)意義。首先,合成了有機溶劑(乙二醇,檸檬酸)修飾的Ni CA-x/Si O2-EG催化劑,對Si O2載體通過不同醇類修飾,考察不同醇類有機助劑修飾Ni基催化劑對甲烷轉(zhuǎn)化率的影響,獲取修飾Si O2載體效果最好的醇類有機物;其次,考察不同含量的檸檬酸對Ni基催化劑物理化學(xué)特性的影響,獲取添加檸檬酸的最佳含量;探索載體修飾和有機助劑添加對催化劑的協(xié)同作用。TPR結(jié)果表明隨著檸檬酸添加量的增加,還原峰向高溫方向移動,這歸因于檸檬酸促進還原后催化劑形成較小的鎳顆粒。TEM、XRD、FT-IR證實了添加有機助劑改性二氧化硅表面可以穩(wěn)固金屬鎳物種,從而防止金屬顆粒在高反應(yīng)溫度下聚合。最后,分別以Al2O3,Si O2為載體,采用不同的浸漬策略(共浸漬法和分步浸漬法)合成釔摻雜的鎳基催化劑,研究了稀土元素釔對催化劑物理化學(xué)特性的改變,探討了浸漬順序?qū)︽嚮呋瘎┙Y(jié)構(gòu)和催化性能的影響。
[Abstract]:Excessive consumption of oil due to rapid industrial development and population growth, The world is concerned about global warming and consumption of limited oil reserves. Methane reforming can convert methane into high value-added syngas such as H _ 2 and CO _ 2, which can then be converted into a variety of chemical products, such as methanol, In this thesis, the modification and synthesis strategy of nickel based catalyst were studied in detail. The yttrium-doped nickel-based catalysts supported on silica and alumina were synthesized by different impregnation strategies (step-by-step impregnation and co-impregnation). The catalytic performance of nickel-based catalysts in methane reforming was studied in detail. The structure of the catalyst was characterized by X-ray powder diffraction (XRD), nitrogen adsorption-desorption curve, temperature programmed reduction (TPRT), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TG). The key role of organic auxiliaries in improving catalytic performance was systematically explained, and the effects of synthesis strategies (co-impregnation and stepwise impregnation) of yttrium-containing catalysts on the catalytic performance of Al _ 2O _ 3 and Sio _ 2 catalysts with different supports were discussed. The influence of impregnation method on different carriers was revealed. The results further illustrate the advantages of additive addition and carrier modification in the structure and catalytic performance of nickel based catalysts. The research results in this paper are very important for the improvement of existing nickel based reforming catalytic systems. The guiding significance. First of all, Ni CA-x/Si O 2-EG catalyst modified by organic solvent (ethylene glycol, citric acid) was synthesized. The effect of different alcohols on methane conversion of Ni based catalyst modified by different alcohols was investigated. Secondly, the effects of citric acid on the physical and chemical properties of Ni based catalyst were investigated, and the optimum content of citric acid was obtained. The results showed that the reduction peak shifted to high temperature with the increase of citric acid content. This was attributed to the fact that citric acid promoted the formation of smaller nickel particles after reduction. TEMN XRDX FT-IR confirmed that the surface of silicon dioxide modified by organic additives could stabilize the metal nickel species and thus prevent metal particles from polymerizing at high reaction temperature. Yttrium doped nickel based catalysts were synthesized by different impregnation strategies (co-impregnation method and stepwise impregnation method) using Al _ 2O _ 3-Si _ 2O _ 2 as the carrier. The physical and chemical properties of the catalyst were studied by changing the rare earth element yttrium. The effect of impregnation order on the structure and catalytic performance of nickel-based catalyst was discussed.
【學(xué)位授予單位】：華南理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：O643.36;TE665.3

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本文編號：1521666