Approach to High Performance Electrode Catalysts for DMFC

DMFC 高性能电极催化剂的研究方法

基本信息

批准号：
13134203
负责人：
TATSUMI Takashi
金额：
$ 47.1万
依托单位：
Tokyo Institute of Technology (2005)Yokohama National University (2001-2004)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2005
项目状态：
已结题

项目摘要

The mesoporous carbons were synthesized by using mesoporous silica materials such as MCM-48 and SBA-15 as a template, respectively. Typically, the templates were impregnated with sucrose as a carbon source and sulfuric acid as an acid catalyst. Following dehydration-condensation of the carbon source, the carbonization was carried out mainly at 900℃ under flowing argon. The silica was removed from the silica-carbon composite by treating it with hydrofluoric acid, producing mesoprpus carbons CMK-1, CMK-3, and CMK-5. Another type of carbon has been also synthesized by using petroleum pitch. MCF carbons can be synthesized by using MCF silica as a template. A carbon structure composed of spherical hollows with closed walls with mesopores of around 4 nm in diameter is prepared by the two-step impregnation of sucrose followed by carbonization. The mesoporous structure was maintained up to 1400℃. Platinum is loaded on these mesoporous carbons. TEM observations revealed the presence of metal particles of below 2 nm in the mesoporous material treated at 1100℃. The metal dispersion is highly dependent not only on the carbon structures but also on the temperature for thermal treatments in inert gas atmosphere. The latter is interpreted in terms of the change in the surface functional groups and their density, which probably affect the interaction of the surface and Pt sources. Oxygen reduction activity of the Pt-loaded electrode on CMK-1 was higher than that of the acetylene derived carbon. The performance of Pt catalyst was affected not only by the Pt dispersion but also by their distribution in the carbon electrode.

分别以MCM-48和SBA-15等介孔二氧化硅材料为模板，以蔗糖为碳源，以硫酸为酸催化剂，然后进行脱水缩合，合成介孔碳。碳源主要在900℃、流动氩气下进行碳化，从硅碳复合材料中除去二氧化硅。通过用氢氟酸对其进行处理，可以通过使用MCF二氧化硅作为模板来合成另一种类型的碳CMK-1、CMK-3和CMK-5。通过蔗糖的两步浸渍和碳化制备了由具有封闭壁的球形空心和直径约为4 nm的中孔组成的碳结构。介孔结构在高达 1400℃ 的温度下仍保持不变。TEM 观察表明，在 1100℃ 处理的介孔材料中存在 2 nm 以下的金属颗粒。金属分散度不仅取决于碳结构。还涉及惰性气体气氛中热处理的温度，后者根据表面官能团及其密度的变化来解释，这可能会影响表面和 Pt 的相互作用。 CMK-1上负载Pt的电极的氧还原活性高于乙炔衍生的碳。Pt催化剂的性能不仅受到Pt分散的影响，而且还受到它们在碳电极中的分布的影响。