本文選題：氧化鋁 + 干氣重整��； 參考：《南京大學(xué)》2015年碩士論文

【摘要】：甲烷二氧化碳重整或甲烷水二氧化碳雙重整制合成氣,進而通過合成氣轉(zhuǎn)化成多種重要化學(xué)品是天然氣有效利用的重要途徑。這一反應(yīng)目前還沒有應(yīng)用到實際工業(yè)中的重要原因就是仍沒有研制出一種高穩(wěn)定、高活性、價格低廉的催化劑。本論文主要圍繞此課題展開工作,以傳統(tǒng)催化劑反應(yīng)理論為基礎(chǔ),通過合理設(shè)計、合成針對甲烷二氧化碳重整或甲烷水二氧化碳雙重整反應(yīng)的高效催化劑,提出了一條獲得在苛刻反應(yīng)條件下保持高活性、高穩(wěn)定性催化劑的可行路線,為該系列反應(yīng)真正實現(xiàn)工業(yè)化打下一定基礎(chǔ)。主要工作如下：1.針對催化劑活性中心的燒結(jié)以及活性中心及載體上的積碳導(dǎo)致催化劑失活的這一原因,本工作通過詳細分析其中的物理化學(xué)機制,采用相應(yīng)解決辦法,各個擊破。首先,制備出CuNi合金納米顆粒并將其負載在y-Al_2O_3載體上一克制催化劑活性中心上的積碳。實驗結(jié)果證明,此方法確實可以有效抑制反應(yīng)過程中活性中心因為積碳而導(dǎo)致的不穩(wěn)定,催化劑能夠維持長時間的高活性;其次,預(yù)先在γ-Al_2O_3載體表面沉積一層氧化鋯以克制載體上的積碳,同時減弱CuNi合金納米顆粒與載體的相互作用,防止合金中銅組分在高溫下與氧化鋁載體反應(yīng),以達到穩(wěn)定合金結(jié)構(gòu)的目的;最后,在沉積CuNi合金納米顆粒之后,再沉積一層氧化鋯,以有限包裹CuNi合金顆粒防止活性顆粒達到燒結(jié)長大。實驗結(jié)果證明,通過上述方法得到的催化劑,在甲烷二氧化碳干氣重整的條件下,具有長期運行的高活性和高穩(wěn)定性。2.實際反應(yīng)中,由于逆水汽變換反應(yīng)通道的存在,甲烷二氧化碳干氣重整得到的合成氣比例組成中,H_2/CO1,這種組成將限制后續(xù)工業(yè)應(yīng)用的范圍。通過往反應(yīng)體系中加入一定比例的水,即實現(xiàn)雙重整反應(yīng),可以實現(xiàn)對合成氣組成的控制。在前述工作的基礎(chǔ)上,本論文進一步考察了經(jīng)過兩次氧化鋯修飾的CuNi合金催化劑在甲烷水二氧化碳雙重整條件下的催化反應(yīng)性能,證實這樣的催化劑,即使在有水的高溫反應(yīng)條件下,也能維持相當時間的高活性和高穩(wěn)定性。通過多種譜學(xué)手段表征了催化劑的結(jié)構(gòu)以及在催化反應(yīng)中的變化過程,為進一步掌握該類型催化劑的實際應(yīng)用提供了寶貴的基礎(chǔ)研究成果。
[Abstract]:Methane carbon dioxide reforming or methane water carbon dioxide dual integration to syngas, and then converted to a variety of important chemicals through syngas is an important way for the effective use of natural gas.The main reason why this reaction has not been applied to practical industry is that a catalyst with high stability, high activity and low price has not been developed.Based on the theory of traditional catalyst reaction, this thesis mainly focuses on the synthesis of high efficiency catalyst for methane carbon dioxide reforming or methane water carbon dioxide dual integral reaction through reasonable design.A feasible way to obtain the catalyst with high activity and high stability under harsh reaction conditions was put forward, which laid a foundation for the industrialization of the series of reactions.The main work is as follows: 1.In view of the reason that the sintering of the active center of the catalyst and the carbon deposition on the active center and the carrier lead to the deactivation of the catalyst, the physical and chemical mechanism of the catalyst is analyzed in detail, and the corresponding solutions are adopted.Firstly, the CuNi alloy nanoparticles were prepared and loaded on the y-Al_2O_3 support to restrain the carbon deposition on the active center of the catalyst.The experimental results show that this method can effectively suppress the instability of the active sites caused by carbon deposition in the reaction process, and the catalyst can maintain high activity for a long time.A layer of zirconia was deposited on the surface of 緯 -Al _ 2O _ 3 carrier in advance to restrain carbon deposition on the carrier, and at the same time, the interaction between the CuNi alloy nanoparticles and the carrier was attenuated so as to prevent the copper component in the alloy from reacting with the alumina carrier at high temperature.Finally, after depositing CuNi alloy nanoparticles, a layer of zirconia was deposited to prevent the active particles from sinter and grow.The experimental results show that the catalyst obtained by the above method has high activity and stability for a long time under the condition of methane carbon dioxide dry gas reforming.In the actual reaction, due to the existence of the reverse water vapor shift reaction channel, the proportion of synthetic gas obtained from the methane carbon dioxide dry gas reforming is H _ 2 / CO _ 1, which will limit the scope of subsequent industrial application.The composition of syngas can be controlled by adding a certain proportion of water to the reaction system.On the basis of the above work, the catalytic properties of CuNi alloy catalysts modified by zirconia were further investigated under the condition of methane, water and carbon dioxide.Even under the condition of high temperature reaction with water, high activity and high stability can be maintained for a certain period of time.The structure of the catalyst and the changing process in the catalytic reaction were characterized by various spectroscopic methods, which provided valuable basic research results for further understanding the practical application of this type of catalyst.
【學(xué)位授予單位】：南京大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TE665.3

【相似文獻】

相關(guān)碩士學(xué)位論文 前1條

1 管誠悅;甲烷重整制合成氣催化反應(yīng)研究[D];南京大學(xué);2015年

，

本文編號：1761798