| Summary: | 碩士 === 國立中興大學 === 材料科學與工程學系所 === 106 === Proton exchange membrane fuel cells have the advantages of high conversion efficiency, high energy density, fast and easy operation, and zero pollution. However, the production of fuel cells still needs to overcome many challenges. The poor dispersion of catalysts, the high price of platinum, and the difficulty in mastering water management are all problems that cannot improve the performance of PEMFC. Therefore, the first part of the experiment will mainly discuss how to increase the dispersibility of Pt particles on the carbon black carrier. In this study, the surface of carbon black was surface-modified with hydrogen peroxide, and the surface of carbon black was filled with oxygen-containing functional groups to increase the dispersibility of carbon black in water. From the XRD pattern, the Pt particle size decreases from 6.56 nm to 4.26 nm.It was confirmed that the surface treatment of carbon black by hydrogen peroxide really reduce the occurrence of Pt agglomeration.
The second part will combine the one-dimensional carbon black structure with two-dimensional graphene to form a new 3D composite structure. It is expected that the high specific surface area of graphene will increase the dispersion of carbon black and make Pt more distributed during reduction. However, it was found by SEM and TEM that agglomeration occurred, and the current density decreased with the increase of graphene addition, mainly due to the poor interaction between graphene and Pt.
The third part will mainly discuss the coating of graphene on the anode gas diffusion layer to improve water management and use the high conductivity of graphene to reduce the occurrence of polarization. From the contact angle analysis results, it is found that the contact angle decreases with the increase of the amount of reduced graphene oxide coating, indicating that the hydrophilicity is increased, and the wetting effect can be achieved to help the hydrogen ion transfer. At 65°C operating temperature, the power density of coating 2.52mg/cm2 reduced graphene oxide increased from 0.395 W/cm2 to 0.538 W/cm2. It was confirmed that coating graphene oxide on anode gas diffusion layer can really increase efficiency.
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