Preparation and Characterization of Nitrogen Containing mesoporous carbon materials
| Autor: | Hao-Yuan Chen, 陳灝元 |
|---|---|
| Rok vydání: | 2012 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 100 In this study, we use melamine/formaldehyde resin as the carbon precursor; commercial fumed silica as support or hard-template via carbonization composites and removal of silica to prepare mesoporous carbon and change the experimental parameters to investigate formation process and optimization. By changing the particle size of the silica(7nm, 14nm, 20nm), the proportion of silica(25%, 33%, 50%, 60%), carbonization temperature(600℃, 700℃, 800℃, 900℃, 1000℃) and pH value(4.5, 4.0, 3.0, 2.0, 1.0）we found that the formation of mesoporous carbon surface properties is not the same. The experimental results show that 7nm and 14nm in the change of the ratio of silica will affect pore size distribution of mesoporous carbon: 25% and 33% are bimodal porosity（~3nm&18nm）and 50%, 60% are single pore（~3nm）. At lower carbonization temperatures, composites will become flakes and poor-porosity carbon material, there will be a large number of pore structure until the temperature is more than 800℃, 900℃ is the best temperature. Changing the pH of solution also has a huge effect on specific surface area of carbon, the changes is up to 500m2g-1. The highest specific surface area of the experimental conditions for 7nm 33% 900℃ pH~4 is 1345m2g-1. Moreover, we prepared mesoporous carbon by the high nitrogen content of melamine as carbon precursor, so they doped a large number of nitrogen atoms. Nitrogen atoms in the mesopurous carbon material in the literature as a active sites for catalytic fuel cell cathode oxygen reduction reaction, so we look forward to its highly application and development in the future. In this study, we used of nitrogen adsorption/desorption isotherm to measure the carbon surface area, pore size distribution and pore volume, transmission electron microscopy to observe the actual morphology of the carbon material, X-ray photoelectron spectroscopy to know nitrogen content and we also used Raman spectroscopy and X-ray diffraction to investigate the degree of graphitization of the carbon materials. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|