本文選題：乙二醇 + 水相重整制氫��； 參考：《天津大學(xué)》2016年博士論文

【摘要】：化石能源的短缺和高污染使氫氣成為理想的替代能源,以生物質(zhì)為原料制取氫氣極具發(fā)展?jié)摿�。傳統(tǒng)制氫方法H_2產(chǎn)量低、設(shè)備復(fù)雜,水相重整制氫反應(yīng)過(guò)程簡(jiǎn)單,可一步制取H_2,相比其他方法更具優(yōu)越性。Pt系貴金屬催化劑轉(zhuǎn)化率高,H_2產(chǎn)率較低,高昂的成本也限制了該系催化劑的應(yīng)用,Ni系催化劑C-C鍵斷裂能力較強(qiáng),但使用中易失活。針對(duì)上述問(wèn)題,本論文采用等體積浸漬法、共沉淀法、沉積沉淀法和檸檬酸溶膠-凝膠法制備了Pd、NiFeCo和NiFe/CeO_2系列催化劑,考察催化劑的結(jié)構(gòu)特性和乙二醇水相重整制氫反應(yīng)的催化活性,取得的主要成果如下:1.采用等體積浸漬法制備了Pd/γ-Al_2O_3、PdNi/γ-Al_2O_3和Ni/γ-Al_2O_3催化劑研究Ni摻雜的影響。實(shí)驗(yàn)結(jié)果表明,Pd/γ-Al_2O_3催化劑上H_2選擇性和乙二醇轉(zhuǎn)化率分別為38.9%和13.7%,烷烴選擇性僅為11.3%。PdNi/γ-Al_2O_3催化劑上形成了PdNi合金,二者之間存在較強(qiáng)的相互作用,促進(jìn)CO的脫附,提高金屬分散性,H_2選擇性和乙二醇轉(zhuǎn)化率分別提高至49.5%和21.9%。2.采用檸檬酸溶膠-凝膠法制備了NiFeCo催化劑,考察Fe/Co摩爾比和還原溫度對(duì)反應(yīng)結(jié)果的影響。Ni對(duì)C-C鍵斷裂能力較強(qiáng),但甲烷化程度較高;Fe促進(jìn)水汽水汽變換反應(yīng)(WGS)反應(yīng)進(jìn)行,但本身催化活性較低;Co對(duì)FeNi合金的形成有促進(jìn)作用,WGS反應(yīng)活性較高。660℃還原后的NiFeCo催化劑上H_2選擇性和乙二醇轉(zhuǎn)化率分別為99.8%和95.1%,而烷烴選擇性降至1.3%,FeNi合金中Fe/Ni摩爾比對(duì)催化活性有較大影響,但該系列催化劑容易失活。3.考察制備方法對(duì)NiFe/CeO_2催化劑水相重整制氫反應(yīng)的影響。cal-NiFe/CeO_2催化劑上H_2選擇性為75.5%,乙二醇轉(zhuǎn)化率為76.3%,烷烴選擇性為12.5%�？捉Y(jié)構(gòu)良好和大比表面積利于反應(yīng)物和產(chǎn)物的進(jìn)出;FeNi合金與CeO_2存在較強(qiáng)的相互作用,促進(jìn)了催化活性的提高。4.采用沉積沉淀法制備N(xiāo)iFe/CeO_2催化劑,考察Ni/Fe摩爾比對(duì)水相重整制氫反應(yīng)的影響。Fe與Ni之間存在相互作用,提高了FeNi合金在CeO_2表面的分散度,增加了H_2選擇性和乙二醇轉(zhuǎn)化率。CeO_2消除了活性位表面的積碳,抑制了顆粒燒結(jié),提高了催化劑穩(wěn)定性。四種多元醇上H_2選擇性和多元醇轉(zhuǎn)化率按如下順序遞減:甲醇乙二醇丙三醇山梨醇。
[Abstract]:Because of the shortage of fossil energy and high pollution, hydrogen is an ideal alternative energy, and it has great potential to produce hydrogen from biomass. The traditional hydrogen production method H _ 2 has low yield, complex equipment, simple process of hydrogen production by water phase reforming, and can be used to produce H _ 2 in one step. Compared with other methods, the conversion rate of noble metal catalyst based on Pt system is higher than that of other methods, and the yield of H _ S _ 2 is lower than that of other methods. The high cost also limits the application of the catalyst. The C-C bond fracture ability of Ni catalyst is strong, but it is easy to be deactivated. In order to solve the above problems, PdN NiFeCo and NiFe/CeO_2 series catalysts were prepared by equal volume impregnation method, co-precipitation method, deposition precipitation method and citric acid sol-gel method. The structure characteristics of the catalyst and the catalytic activity of ethylene glycol reforming in aqueous phase for hydrogen production were investigated. The main results obtained are as follows: 1. The effects of Ni doping on Pd/ 緯 -Al _ 2O _ 3 / 緯 -Al _ 2O _ 3 and Ni/ 緯 -Al _ 2O _ 3 catalysts were prepared by the same volume impregnation method. The experimental results show that the selectivity of H _ 2 and conversion of ethylene glycol on Pd / 緯 -Al _ 2O _ 3 catalyst are 38.9% and 13.7%, respectively, and the selectivity of alkane is only formed on 11.3%.PdNi/ 緯 -Al _ 2O _ 3 catalyst. There is a strong interaction between the two catalysts to promote the desorption of CO. The selectivity of H2 and the conversion of ethylene glycol were increased to 49.5% and 21.9% respectively. NiFeCo catalyst was prepared by citric acid sol-gel method. The effects of Fe/Co molar ratio and reduction temperature on the results of the reaction were investigated. However, the lower catalytic activity of Co could promote the formation of FeNi alloy. The H-2 selectivity and ethylene glycol conversion on NiFeCo catalyst reduced at 0.660 鈩，

本文編號(hào)：1950646