Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/3414
標題: Supported Pt on multiple wall Carbon Nanotube for the electrode application of Direct Methanol Fuel Cell
多壁奈米碳管擔持Pt於直接甲醇燃料電池
作者: dai, yum-ming
戴永銘
關鍵字: Mg-Ni alloy;奈米介金屬鎂-鎳合金;CVD;Purification of CNTs;Direct Methanol;Catalyst of electrode;奈米碳管成長反應;奈米碳管純化;甲醇燃料電池;電極觸媒
出版社: 化學工程學系
摘要: 
As for the CNT growth over nano-Mg-Ni alloys, the results of XRD, TGA,TEM that the optimum reaction condition nano-Mg-Ni alloy as the catalyst to perform pyrolysis of 100% CH4 to form CNTs with the flow rate about 100 ~ 120 sccm at 650℃. Raman results also indicate that the CNTs are formed as the multi-walled structure. After the purified procedures with both air oxidation at 550℃ and HCl treatment, the purity of CNT reaches to ~100%. Thus, the air oxidation step is crucial for the completed purification. The oxidation with flowing of air at high temperature can reorganize the graphite interlayers and makes the HCl easily to penetrate into the graphite interlayers to dissolve the residual catalyst.
Good methods for increasing activity of catalyst in direct methanol fuel cells are decreasing the particle size of Pt and improving its dispersion. FE-SEM and XRD results indicate that the particle size of Pt supported on CNTs of electrode which synthesis under 120℃ is below 5nm and electrochemical analysis indicates the value of discharge is the best reveals the discharge is related to dispersion and the particle size of Pt.
Compared with Pt supported on carbon black shows the value of discharge of Pt supported on CNTs is much better reveals CNTs have chance to take the place of traditional carbon material.

對以奈米介金屬鎂-鎳合金為催化劑成長奈米碳管的反應而言,根據XRD、TGA、TEM結果顯示,成長奈米碳管的最適化條件為:取奈米鎂-鎳合金為催化劑,於650℃下通入流量為100 ~ 120 sccm的純甲烷,進行熱裂解生成奈米碳管。經由拉曼光譜分析顯示,所製備之奈米碳管皆屬多壁奈米碳管。純化研究結果顯示,將奈米碳管初產物以空氣氧化及鹽酸處理後,其純度幾乎達到100%。在一系列的純化步驟中,奈米碳管的純化完全與否取決於空氣氧化步驟,因為空氣氧化可以使石墨層進行修飾,並使鹽酸容易進入石墨層中將殘存的催化劑溶出。
提昇甲醇燃料電池中觸媒的活性,最好的方法就是將觸媒中之Pt降低顆粒大小及提高其分散性。由FE-SEM、XRD結果得之,在120℃下所製備之白金電極觸媒,其Pt擔持在奈米碳管上的顆粒約在5nm以下,並由電化學分析結果其放電量是最大,顯示電極觸媒放電量與Pt分散性及粒徑大小是相關,分散越均勻、粒徑越小,其放電量越高。
奈米碳管與一般碳黑(m-1100)之比較,發現奈米碳管擔持Pt
後的放電量的明顯的比碳黑擔持Pt後的放電量還大,顯示奈米碳管
有取代傳統碳材的機會。
URI: http://hdl.handle.net/11455/3414
Appears in Collections:化學工程學系所

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