Key facators to the synthesis of high performance anode catalyst for use in DMFC

• Main Authors: Han-Gen Chen, 陳漢根
• Other Authors: 陳郁文
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/10320634369463995630

碩士 === 國立中央大學 === 材料科學與工程研究所 === 95 === There are some criteria for high performance direct methanol fuel cell anode electrocatalysts：The material used as support has high conductivity, reaction centers dispersed homogeneously on support’ s surfaces and the particle size of anode catalysts must be small. In this study we use high surface carbon black, Ketjen Black EC300 , with surface area of 855 m2/g , as the support. In order to increase the hydrophilic ability of EC300 and has a more homogenous dispersed reaction centers, we functionlized these carbon black’s surface by H2O2 and ozone, respectively, and we hope the particle size of catalysts can be reduced by these surface modifications. Temperature Programmed Desorption was used to identify those functional groups created by surface modification of carbon black, Brunauer-Emmett-Teller method was used to check the surface area and porosity of those modified carbon black, and conductivities of these modified carbon black were obtained by four-probe method. We test the methanol oxidation ability of catalysts supported on these modified carbon black by using cyclic volatommetry measurement, and find out the most adaptable carbon black for high performance anode electrocatalysts for use in DMFC. Furthermore, we used NaBH4, HCHO and NaH2PO2 as reduction agents, and research the influence of these agents on electrocatalyst synthesis. These catalysts were characterized by XRD and TEM, components of these catalysts were detected by XRF and XPS, EXAFS had been used to study the microstructure of NaH2PO2-synthesised catalysts. We found that NaH2PO2 can effectively reduce the particle size of the active site of anode catalyst, furthermore better dispersion on carbon black was also accomplished. The catalysts prepares in the study have better performance and in methanol oxidation then commercial, Johnson Matthey H10100 catalysts. Particle size, Pt-Ru ratio on the catalyst surface and conductivity of the carbon support are the key factor contribute to the performance of the catalyst.