奈米材料的尺寸在氧化乙醇蒸氣重組上的影響

Abstract

本論文是在研究多種金屬在氧化鋁上的複合式材料並透過氧化乙醇蒸氣重組(OSRE)的催化現象。首先OSRE已經被我們有系統的研究催化金屬Co、Ni、Cu、Ru、Rh、Pd、Ag、Ir和Pt在氧化鋁顆粒上且比較有煮沸和無煮沸過的氧化鋁的支撐物影響。此外，為了驗證催化劑在OSRE反應中的金屬性質效應，一開始我們先合成奈米金屬Cu、Pd、Ag、Ir、Pt和Au並沉積到氧化鋁的顆粒和粉末上，最後並分析OSRE的反應現象。 在奈米合成方面，我們也探討了界面活性劑、還原劑和金屬前驅物濃度的相對關係，以及控制奈米粒子的尺寸大小和形狀。在沉積部分，奈米粒子與金屬氧化物的吸附與之間的電荷分布關係，也已經被我們有系統的利用燒結溫度、pH值、溶劑、不同種酸、離子效應和不同種金屬氧化物做測試。最後利用TEM、XRD、UV-VIS光譜去做特性鑑定與OSRE的測試。我們可以經由乙醇轉換效率、氫氣產率、產物選擇率去針對複雜的OSRE的反應機制有初步的了解。 結果也發現奈米Cu、Ag、Au可以幫助氧化反應過程。此外，這些奈米材料可以在最適當的氧氣量達到最大氧化能力。

This thesis thoroughly studies the catalytic performance of oxidative steam reforming of ethanol (OSRE) on various metals composited Al2O3. First, OSRE has been systematically investigated on the catalysts of metals of Co, Ni, Cu, Ru, Rh, Pd, Ag, Ir and Pt on Al2O3 particles with and without boiling water treatment to examine the oxide supporter effect. Furthermore, to examine the metallic effect of the catalysts on OSRE, we synthesize the nanoscaled metals of Cu, Pd, Ag, Ir, Pt and Au initially, then deposite the the nanoparticles on Al2O3 particle and powder, and, finally analyze their corresponded OSRE performance. In the nano-synthesis, the surfactants, reductants and concentrations of metal precursors, the important criteria to control the size and shape of nanoparticles, have been extensively investigated. In the deposition process, the metal/oxide adhension corresponds to the charge distribution in their interfaces and have been systematically examined the effects from sintering temperature, pH, solvation, types of acids, counter ions and oxide supporters. Finally, the well fabricated samples have been characterized by TEM, XRD and UV-visible spectroscopy and tested in OSRE. Based on the measurements of ethanol conversion, hydrogen yield and product selectivity, the complicated OSRE mechanism can be fundamentally understood.