| Summary: | 碩士 === 國立高雄應用科技大學 === 化學工程與材料工程系 === 100 === In recent years, due to high energy demands, many researchers focus on developments of various alternative energy and clean energy in order to reduce carbon dioxide emissions. Among them, the fuel cell has advantages such as low pollution, high efficiency, diverse of energy generation. However, the price and stability of the catalysts in fuel cells hindered their practical applications. Therefore, it is urgent to lower the costs of fuel cells. Thus, R&D on fuel cells by using non-noble metals or supported on nitrogen-doped carbons recieve many attentions. Ionic liquids have many unique physical and chemical properties, for instance, negligible vapor pressure, good chemical stability and reusability, can be potential applied in chemical synthesis, electrochemistry, etc.
The main purpose of this study was to prepare the nitrogen-doped carbon nanocomposites by using the different type of ionic liquids such as 1-(3-Aminopropyl)-3-methylimid azolium bromide ([AM][Br]), 1,3- bis(Cyanomethyl)-imidazolium Iodide ([BCN] [I]), 1-Ethyl-3-Methylimi dazolium Dicyanamide ([EMI][DCA]). In addition, the Guanine and ammonium iron(II) sulfate hexahydrate were ultilized as nitrogen-rich sources and metal precursors, respectively to fabricate nitrogen-doped and Fe supported nitrogen-doped carbon nanocomposites.
A variety of different spectroscopic and analytical techniques, such as Fourier Transform Infrared Spectroscopy (FT-IR), Nuclear Magnetic Resonance (NMR), Small Angle X-ray Scattering (SAXS), Powder X-ray Diffraction (PXRD), Brunauer-Emmet-Teller (BET) analysis, Atomic Absorption Spectrometry (AAS), Elemental Analysis (EA), X-ray Photoelectron Spectroscopy (XPS) and Transmission Electron Microscopy (TEM) were used to characterizethe physicochemical properties of various materials. In addition, the performance of the cathodic electrocatalysts during oxygen reduction reaction (ORR) was also investigated by using linear sweep voltammetry (LSV).
We use different type of ionic liquids, nucleobases and various amounts of iron (1, 5, 10 wt %) to synthesize nitrogen-doped and Fe supported nitrogen-doped carbon nanocomposites. Results obtained from this study revealed that the 5 wt% of iron contents in the catalysts show the best performance for ORR. Moreover, the carbonization temperatures (600, 800 and 1000 ℃) were also investigated. The results of LSV experiments indicated that the ORR activities may be related to the high surface area of catalysts with the increase of carbonization temperatures.
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