發(fā)布時間：2018-06-27 15:08

  本文選題：CO氧化 + CuO-CeO_2催化劑　； 參考：《浙江師范大學(xué)》2016年碩士論文

【摘要】：眾所周知,CO的催化氧化反應(yīng)因為其重要的學(xué)術(shù)和實際應(yīng)用價值在催化領(lǐng)域中占有舉足輕重的地位,成為人們爭相研究的熱點(diǎn)。目前已有文獻(xiàn)證明：催化劑的載體成分和表面的活性組分—金屬物種的協(xié)同作用對CO催化氧化反應(yīng)有很明顯的促進(jìn)作用。隨著多孔材料的興起和發(fā)展,我們將多孔材料的高比表面積、大孔容、發(fā)達(dá)的孔結(jié)構(gòu)等優(yōu)點(diǎn)應(yīng)用于傳統(tǒng)的CO催化氧化催化劑中,研究催化劑的形貌是否能對催化劑的活性有明顯的提高作用。在本文中,我們利用PMMA(聚甲基丙烯酸甲酯)這種硬模板劑和三嵌段共聚物P123這種表面活性劑制備了一系列3DOMCuO-CeO_2催化劑(三維有序大孔CuO-CeO_2催化劑),并應(yīng)用于CO催化氧化反應(yīng)研究中。利用KIT-6為模板劑制備了PdO/meso-CeO_2和]meso-PdO-CeO_2兩種催化劑。我們利用XRD, TEM, SEM, BET, H2-TPR, Raman, XPS以及原位FT-IR等表征方法對催化劑的結(jié)構(gòu)等進(jìn)行了表征；結(jié)合表征結(jié)果和活性數(shù)據(jù)闡述催化劑中金屬與載體的協(xié)同作用以及多孔結(jié)構(gòu)對反應(yīng)的影響。本論文主要內(nèi)容如下：1.利用PMMA作為硬模板劑和三嵌段共聚物P123作為表面活性劑制備了一系列具有三維有序大孔(3DOM)結(jié)構(gòu)的CuO-CeO_2催化劑,分別考察了3DOMCuO-CeO_2催化劑中的CuO負(fù)載量和三維立體結(jié)構(gòu)對CO催化氧化性能的影響。研究結(jié)果表明：當(dāng)CuO負(fù)載量為20%時的20CuO-CeO_2-D催化活性最好,且催化活性明顯優(yōu)于通過等體積浸漬法制備的催化劑。這可能是由于三維有序大孔結(jié)構(gòu)和三嵌段共聚物P123的使用大大提高了催化劑的比表面積,這有利于CuO顆粒在催化劑表面上分散度的提高。2.以KIT-6為模板劑,分別用不同的負(fù)載方法：“后負(fù)載法”和“一步法”制備出PdO/meso-CeO_2和]meso-PdO-CeO_2催化劑：用等體積浸漬法和溶膠凝膠法分別制備了PdO/CeO_2和PdO-CeO_2催化劑。結(jié)果表明：對于同種負(fù)載方法制備的催化劑,介孔結(jié)構(gòu)催化劑活性較好；對于相同結(jié)構(gòu)的催化劑,“后負(fù)載法”制備的催化劑活性明顯高于通過“一步法”制備的催化劑,進(jìn)一步說明在CO催化氧化反應(yīng)中,起主要作用的是表面Pd及PdO物種,而不是Ce-Pd-O固溶體中的Pd~(n+)。
[Abstract]:It is well known that the catalytic oxidation of carbon monoxide (CO) plays an important role in the field of catalysis because of its important academic and practical application value. At present, it has been proved that the synergistic effect of the carrier composition and the active component on the surface of metal species has a significant effect on the catalytic oxidation of CO. With the rise and development of porous materials, the advantages of porous materials such as high specific surface area, large pore volume and developed pore structure are applied to the traditional catalysts for CO catalytic oxidation. Whether the morphology of the catalyst can improve the activity of the catalyst is studied. In this paper, a series of 3DOMCuO-CeO2 catalysts (three dimensional ordered macroporous CuO-CeO2 catalysts) have been prepared by using PMMA (polymethyl methacrylate), a hard template and triblock copolymer P123, which have been applied to the catalytic oxidation of CO. Two kinds of catalysts, PdO / meso-CeOs _ 2 and] meso-PdO-CeOS _ 2, were prepared by using KIT-6 as template. The structure of the catalyst was characterized by XRD, TEM, SEM, BET, H2-TPR, Raman, XPS and in situ FT-IR, and the synergistic effect of metal and support in the catalyst and the effect of porous structure on the reaction were described by combining the characterization results and the activity data. The main contents of this thesis are as follows: 1. A series of CuO-CeO _ 2 catalysts with three-dimensional ordered macroporous (3Dom) structure were prepared by using PMMA as hard template and triblock copolymer P123 as surfactant. The effects of CuO loading and three-dimensional structure on the catalytic oxidation of CO in 3DOMCuO-CeO2 catalyst were investigated. The results show that the catalytic activity of 20CuO-CeO2-D is the best when the CuO loading is 20 and the catalytic activity is obviously better than that prepared by the iso-volume impregnation method. This may be due to the use of three-dimensional ordered macroporous structure and triblock copolymer P123, which greatly improves the specific surface area of the catalyst, which is beneficial to the increase of the dispersion of CuO particles on the surface of the catalyst. Using KIT-6 as template, PdO / P / CEO _ 2 and] meso-PdO-CeO _ 2 catalysts were prepared by "post-loading method" and "one-step method", respectively. PdO _ (p-CeO _ (2) and PdO-CeO _ (2) catalysts were prepared by iso-volume impregnation method and sol-gel method, respectively. The results showed that the mesoporous structure catalyst had better activity for the same supported catalyst, and for the same structure catalyst, the activity of the catalyst prepared by "post-supported method" was obviously higher than that prepared by "one-step method". It is further indicated that PD and PDO species on the surface play a major role in CO catalytic oxidation, rather than PD ~ (n). In Ce-Pd-O solid solution.
【學(xué)位授予單位】：浙江師范大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：O643.36

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相關(guān)期刊論文 前1條

1 吳世華,黃唯平,張守民,魏偉,張淑紅,鄭修成;溶劑化金屬原子浸漬法制備高分散Au/TiO_2低溫CO氧化催化劑[J];催化學(xué)報;2000年05期

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本文編號：2074323