| Summary: | 碩士 === 國立中央大學 === 能源工程研究所 === 102 === How to increase catalyst utilization and activity are very important in PEMFC. Carbon black is widely used today as the catalyst support. Although current practice of using carbon black to support catalyst can enhance catalyst dispersion and catalytic activity, it suffers from loss of catalytic use due to occasional island formation. This can be prevented by using continuous catalyst support. Ordered porous carbon (OPC) is used as the catalyst support for fuel cell application due to its large surface area and continuous structure.
We will prepare continuous and ordered structure of porous carbon as catalyst support for PEMFC to improve the catalyst utilization and enhance electron transfer. Pt-M alloy catalysts have higher activity than pure Pt catalysts. The noble metal, Sn, is a promising candidate to replace Pt not only reduces cost by lowering Pt loading but also increases ORR activity in acidic environment of fuel cell.
Results show that PtSn/OPC as prepared has well dispersed PtSn nano particles, with an average particle size around 2.6 nm. Compared XRD patterns with pure Pt’s, the reflection peak associated with the Pt(111) of PtSn samples is slightly shifted from 39.8° to about 39.3°, indicating the formation of a solid solution involving the incorporation of Sn atoms into the lattice of Pt. The electrochemically active surface area of PtSn/OPC samples is found to be higher than that of Pt/C. During long-term stability, due to the confining effects of mesopores of OPC on Pt-Sn particles, the Pt-Sn/OPC catalyst exhibits better long-term durability than Pt/C. Therefore, the Pt-Sn/OPC catalyst is promising as a durable and robust cathode catalyst for PEMFCs.
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