本文選題：介孔二氧化硅 + 乙醇水蒸氣重整制氫　； 參考：《太原理工大學(xué)》2015年碩士論文

【摘要】：有序介孔二氧化硅屬于分子篩范疇，因其比表面積高、孔容量大、孔徑可調(diào)、耐熱性好等特點而成為研究的熱點。現(xiàn)階段對有序介孔二氧化硅的研究主要圍繞著用有機物擴孔、以其為模板劑制備其它納米線或納米絲材料等方面來進(jìn)行。然而，因其形貌、孔道的單一性以及有機物擴孔方法的不環(huán)保性等缺點，在一定程度上限制了其應(yīng)用。 本文基于研究現(xiàn)狀的局限性，從有序介孔二氧化硅合成（S0H+X-I+）機理入手，調(diào)節(jié)合成過程中母液的種類和濃度（H+X-來源），將傳統(tǒng)鹽酸母液換作硝酸、硫酸和磷酸母液，合成出的SBA-15的形貌分別為“麥穗”狀、“銅錢”狀、長程連續(xù)“糖塊”狀和高度分散“糖塊”狀，形貌間差別很大�？紤]到合成過程最為重要的兩個步驟就是水浴和水熱處理。水浴過程主要是模板劑與硅源間的相互作用合成出初始二氧化硅材料，晶化過程主要是將合成出的初始材料進(jìn)一步晶化，孔壁變薄變堅硬。將合成過程的兩個步驟分別調(diào)控酸度，再結(jié)合母液種類的不同，最終合成出了雙介孔二氧化硅材料。通過以上簡單環(huán)保的方法，在一定條件下就可以制備不同形貌和雙介孔狀的二氧化硅材料。 鎳對乙醇水蒸氣重整制氫反應(yīng)有較好的活性，但鎳易燒結(jié)，尤其在通常選擇的酸性或表面積較小的載體中更易燒結(jié)。載體若顯酸性還會使氣體產(chǎn)物有乙烯，乙烯的存在又會使氫氣產(chǎn)率降低。本論文中制備的SBA-15，比表面積較大且為中性，比表面積較大就會使得負(fù)載金屬量較大而不發(fā)生燒結(jié)，是很好的用在該反應(yīng)的催化劑載體。本實驗的另一部分就是以SBA-15為催化劑載體，采用兩種不同的鎳源（硝酸鎳、氨基磺酸鎳）制備催化劑，通過XPS、TEM等手段表征催化劑的物化性能的差異，最終發(fā)現(xiàn)兩種鎳源負(fù)載到載體的位置不同，硝酸鎳主要負(fù)載到催化劑孔道，氨基磺酸鎳主要負(fù)載到載體表面，并且經(jīng)還原后鎳的晶型不同，，導(dǎo)致了催化后產(chǎn)物相差很大。通過改變反應(yīng)過程的進(jìn)料量和溫度得到實驗數(shù)據(jù)，并通過MATLAB程序中的LevenbergMarquardt和lsqcurvefit算法對實驗數(shù)據(jù)進(jìn)行擬合，最終得到對催化劑Ni(1)7.5SBA在550℃左右反應(yīng)活化能為25.345KJ mol-1，對催化劑Ni(2)7.5SBA在500℃左右反應(yīng)活化能為41.449KJ mol-1等本征動力學(xué)數(shù)據(jù)。從物化性能參數(shù)和本征動力學(xué)數(shù)據(jù)兩個方面說明兩種鎳源催化劑催化效果差異的原因。進(jìn)一步考查了兩種催化劑的活性金屬負(fù)載量、壽命、進(jìn)料中水醇比等工藝參數(shù)，為其進(jìn)一步工業(yè)的應(yīng)用提供了基礎(chǔ)研究。
[Abstract]:Ordered mesoporous silica belongs to molecular sieve and has become a hot research area due to its high specific surface area, large pore capacity, adjustable pore size and good heat resistance. At present, the study of ordered mesoporous silica is mainly focused on the preparation of other nanowires or nanowires using organic compounds as templates. However, its application is limited to some extent because of its morphology, the uniqueness of the pore channel and the unenvironmental protection of the organic pore expansion method. In this paper, based on the limitation of the present research situation, starting with the synthesis mechanism of ordered mesoporous silica, we adjust the type and concentration of mother liquor and change the traditional hydrochloric acid mother liquor into nitric acid, sulfuric acid and phosphoric acid mother liquor. The morphology of the synthesized SBA-15 is "wheat spike" shape, "copper money" shape, long range continuous "sugar block" shape and highly dispersed "sugar block" shape. Considering that the two most important steps in the synthesis process are water bath and hydrothermal treatment. The main process of water bath is the interaction between the template and the silicon source to synthesize the initial silica material. The crystallization process is mainly to further crystallize the synthesized initial material and the pore wall becomes thinner and harder. The dimesoporous silica materials were synthesized by adjusting the acidity of the two steps of the synthesis process and combining with the different kinds of mother liquor. Under certain conditions, silicon dioxide with different morphology and double mesoporous structure can be prepared by the simple environmental protection method mentioned above. Nickel has good activity for ethanol steam reforming to produce hydrogen, but nickel is easy to sintered, especially in usually selected carriers with less acid or surface area. If the carrier is acidic, the gas product will have ethylene, and the presence of ethylene will reduce the hydrogen yield. The SBA-15 prepared in this paper has a large specific surface area and a neutral surface area, which will lead to a large amount of supported metals without sintering, so it is a good catalyst carrier for this reaction. The other part of this experiment is to prepare the catalyst with two different nickel sources (nickel nitrate and nickel aminosulfonic acid) using SBA-15 as the catalyst carrier, and to characterize the difference of the physical and chemical properties of the catalyst by means of XPS Tem. Finally, it was found that the two kinds of nickel sources were loaded to the carrier in different positions. Nickel nitrate was mainly supported on the catalyst pore, and nickel aminosulfonic acid was mainly loaded on the surface of the carrier. After the reduction, the crystal form of nickel was different, which led to the great difference of the product after the catalyst. The experimental data are obtained by changing the feed amount and temperature of the reaction process, and the experimental data are fitted by the LevenbergMarquardt and lsqcurvefit algorithms in the MATLAB program. Finally, the activation energy of the reaction of the catalyst Ni(1)7.5SBA at 550 鈩

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