【作者】 王福兵；

【导师】 田建华；

【作者基本信息】 天津大学 ， 应用化学， 2004， 硕士

【摘要】 质子交换膜燃料电池（PEMFC）具有高能量密度、运行温度低和稳定性能较好等优点，在航天领域、潜艇、电动车、飞船等领域有广泛的应用前景。目前，虽然 PEMFC 的各项技术已经趋于成熟，正处于大规模商业化应用的前夜。为使PEMFC 能够早日实现商品化生产，各国科研工作者正在致力于相关材料的研究，力图降低 PEMFC 成本，提高相关材料的性能。其中包括高性能 Pt/C 电催化剂的研究。 本实验研究了 Pt/C 电催化剂制备的浸渍还原法，其中主要包括载体碳黑的热处理技术。通过优化碳黑热处理的工艺条件，如温度和环境，使碳黑载体的性能得到明显改善。采用 TEM、XRD、XPS、CV、MEA 等测试手段对所制备的Pt/C 电催化剂性能进行了全面的分析。Pt/C 电催化剂的 TEM 照片显示，采用氮气氛中 600℃热处理的碳黑载体制备的 Pt/C 催化剂中 Pt 颗粒的平均粒径为3.3nm，降低了约 1nm；分散度也有了一定的提高。碳载体的 XRD 和 XPS 测试说明，热处理使碳载体表面组成发生了变化，使其更有利于生成颗粒细小且均匀的 Pt/C 电催化剂。 本实验还研究了胶体法制备 Pt/C 电催化剂的相关工艺。研究工作包括胶体的稳定性和不同的还原剂和浓度对 Pt/C 电催化剂性能的影响。采用经优化的胶体法制备工艺，所制备的 Pt/C 电催化剂中 Pt 颗粒的平均粒径为 3.05nm，已经接近 Johnson Mattey 公司的 Pt/C 电催化剂水平。 为了提高催化活性和防止催化剂在使用过程中的团聚，本实验还初步探讨了在Pt/C电催化剂中引入金属助剂Re。实验采用分步浸渍还原法，在制备过程中首先用Fe/H2SO4把KReO4还原成Re的氧化物ReO3， 然后用H2在高温下把ReO3还原成Re，最后在Re/C上沉积Pt得到PtRe/C电催化剂。采用循环伏安法表征了PtRe/C电催化剂的性能，证明了其较好的电催化活性。更多还原

【Abstract】 The proton exchange membrane fuel cell (PEMFC) is a highly attractive powersource for mobile and stationary applications due to its high power density at lowertemperatures and its compact design. At present, a large amount of work has beendevoted to reduce the material costs of PEMFCs to achieve their widespreadapplication, including the method of preparing a Pt catalyst with a large specificsurface area to minimize the amount (and cost) of Pt required for a given level ofactivity. This paper presents a detailed study of the impregnation-reduction method forthe preparation of Pt/C catalysts，including the heat-treatment technology for thetreatment of the carbon black support. The carbon black supports heat-treated in N2stream at 600℃ exhibit a positive role of promoting Pt dispersion to a higher degree.The particle size and the dispersion degree of Pt supported on carbon are observed byTEM. The surface structure and composition of supports and Pt/C electrocatalysts areanalyzed by XRD and XPS. The results show that the performance of Pt/Celectrocatalysts is improved a lot. The supported Pt/C electrocatalysts about 3.3nmplatinum crystallites have been prepared by this method. This paper has also studied the colloid method for preparing Pt/C electrocatalysts,concluding the colloid stability, both the different reducers and the solutionconcentrations which affect the performance of Pt/C electrocatalysts. The preparedPt/C electrocatalysts has an average platinum crystallite of 3.05nm which is similar tothat of Johnson Mattey catalyst. This paper has studied the preparation method of PtRe/C catalysts. PtRe/Ccatalyst has been successfully prepared by the impregnation-reduction method. Theprocess includes two steps. First, the reagent Fe/H2SO4 is used to reduce KReO4 toReO3, and then H2 is used to reduce ReO3 to metal Re. The so obtained Re/C isimpregnated in H2PtCl6 solution and reduced to PtRe/C by HCHO solution. CV method isused to evaluate the electrochemical performance of the prepared PtRe/C.更多还原