本文選題：納米催化　切入點：有序介孔碳　出處：《合肥工業(yè)大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：催化劑是工業(yè)生產(chǎn)和科學(xué)研究的重要內(nèi)容,對于納米催化而言,催化劑的穩(wěn)定性以及可接觸性是影響其在各個催化體系應(yīng)用的重要因素。從這兩個角度出發(fā),本文設(shè)計了兩種新型負載型貴金屬納米催化劑,旨在得到穩(wěn)定性良好、可接觸性良好的模型催化劑。多孔碳是高溫催化劑載體的優(yōu)選對象,本文結(jié)合膠體納米顆粒的組裝工藝,通過組裝多成分(氧化鐵、貴金屬)的三維有序膠體球,在惰性氣氛下對膠體球進行碳化處理,膠體納米顆粒單體表面的有機活性劑將原位地碳化成介孔的結(jié)構(gòu),再通過鹽酸的選擇性刻蝕作用除去氧化鐵納米顆粒,最終得到分散性良好的耐高溫的負載型貴金屬納米催化劑。所制備的三維有序介孔碳具有1461.0653 m2·g-1超高比表面,介孔尺寸大小7.5 nm,為可以耐受1000℃的高溫而不發(fā)生明顯的結(jié)構(gòu)坍縮現(xiàn)象;由于三維有序介孔碳的空間限域作用,所制備的金負載的三維有序介孔碳納米催化劑能夠經(jīng)受800℃的高溫而未發(fā)生明顯的團聚現(xiàn)象,而良好的介孔結(jié)構(gòu)同時保證了該負載型催化劑在催化反應(yīng)體系中良好的可接觸性;該設(shè)計路線同時適用于其他貴金屬催化劑,如我們將之推廣至鈀基的負載型高溫催化劑。用乙炔處理鈀負載的ZIF-67表面,利用鈀對乙炔良好的加聚作用,在其表面包覆了聚乙炔層。該疏水性的聚乙炔膜提高了鈀催化劑的可接觸性,同時也提高了 ZIF-67表面的水穩(wěn)定性,經(jīng)水的刻蝕作用最終得到空心結(jié)構(gòu)的鈀基負載型催化劑。聚乙炔膜的引入不僅使得催化劑的水穩(wěn)定性極大提高,研究結(jié)果表明,本課題所制備的空心結(jié)構(gòu)能夠在沸水中穩(wěn)定存在;同時在催化性能上也有明顯的提升,表現(xiàn)為催化活性提升了近40%。
[Abstract]:Catalyst is an important content in industrial production and scientific research. For nanocatalysis, the stability and accessibility of catalyst are important factors affecting its application in various catalytic systems. In this paper, two new supported noble metal nanocatalysts are designed to obtain model catalysts with good stability and good contact. Porous carbon is the best choice object for high temperature catalyst support. In this paper, the assembly process of colloidal nanoparticles is combined. By assembling three-dimensional ordered colloidal spheres with multi-component (iron oxide, precious metal), the colloidal spheres were carbonized in inert atmosphere, and the organic active agents on the surface of colloidal nanoparticles carbonized in situ to form mesoporous structures. After selective etching of hydrochloric acid to remove the iron oxide nanoparticles, the supported noble metal nanocatalysts with good dispersion and high temperature resistance were obtained. The prepared three-dimensional ordered mesoporous carbon has 1461.0653 m2 路g-1 ultra-high specific surface. The mesoporous size is 7.5 nm, which can withstand high temperature at 1000 鈩，

本文編號：1560479