硅基微型燃料电池用双导性高分子聚合膜的基础研究

项目名称： 硅基微型燃料电池用双导性高分子聚合膜的基础研究

项目编号： No.20803025

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 化学工业

项目作者： 冯春华

作者单位： 华南理工大学

项目金额： 20万元

中文摘要： 基于微机电系统（MEMS）技术的微型燃料电池是一种利用成熟的集成电路加工工艺，在半导体材料上加工的微型反应器。但是由于低的电极催化性能其功率密度远小于传统燃料电池。本项目中，在硅基电极中引入高分子导电膜聚吡咯（PPy）作为中间层，用以导连硅衬底和纳米金属催化剂。电化学合成的PPy/Nafion?复合膜用作催化剂载体，具备良好且可控的电子、质子传导率以及高的比表面积，改善了电极复合材料的电催化性能。模拟阻抗谱图得出最佳合成的导电膜电子以及质子传导率分别为0.16和2.0×-3 S cm-1。纳米催化剂Pt与聚合物之间的协同作用提高了Pt/PPy/Nafion?复合电极对CO以及CH3OH的催化作用。以Pt/PPy/Nafion?/μi 为电极的硅基氢氧微型燃料电池的功率密度为23.4 mW cm-2，比不加聚合物导电膜的电池性能提高8倍。以PtRu/PPy/Nation?/μi 为电极的硅基甲醇微型燃料电池的功率密度远高于文献中报道值。本项目通过对导电聚合膜的特性如比表面积、导电子和导质子能力等开展基础研究，还拓展了其在化学能源电极材料（如超级电容器、微生物燃料电池）的应用。

中文关键词： 导电聚合物；微型燃料电池；微机电系统；聚吡咯；电化学阻抗

英文摘要： Si-based micro fuel cell (MFC) prototypes leveraging the well-documented microelectromechanical system (MEMS) techniques have been demonstrated. One of the outstanding issues that limit the power output of MFCs is the low-performance Si-based electrocatalyst system. To address this issue, we used the conductive film as a catalyst support to host the electrochemically deposited catalyst nanopartilces (e.g. Pt and PtRu). This supporting material (e.g. polypyrrole(PPy)/Nafion?), fabricated on a Si substrate via the electropolymerization method, provided good electron conductivity and high surface area to facilitate the incorporation of electrocatalysts. In addition, the synthesized polymer offered high proton conductivity in order to enhance the transport of protons within the catalyst layer and consequently extend the 3D reaction zones and maximize the utilization of catalysts. By fitting the electrochemical impedance (EIS) data with the transmission-line model, the optimized PPy/Nafion? composite film possesses electron conductivity of 0.16 S cm-1 and proton conductivity of 2.0 ×0-3 S cm-1. The Si-based H2-O2 micro fuel cell equipped with the Pt/PPy/Nafion?/micro Si electrodes exhibits a maximum power density of 23.4 mW cm-2, increased by 8 times as compared to that obtained with Pt/micro Si electrodes. The Si-based methanol micro fuel cell with the PtRu/PPy/Nafion?/micro Si electrodes shows a much higher power density than the literature data. In this project, we also demonstrated the application of the PPy conductive polymers as electrode materials in supercapacitors and microbial fuel cells.

英文关键词： Conductive polymer; Micro fuel cell; Microelectromechanical system (MEMS); Polypyrrole; Electrochemical impedance spectra