【作者】 侯中军；

【导师】 衣宝廉；

【作者基本信息】 中国科学院研究生院（大连化学物理研究所） ， 化学工程， 2003， 博士

【摘要】 氢源问题是质子交换膜燃料电池（PEMFC）技术发展和广泛应用的一个重要课题，采用重整气为燃料是目前从经济成本和技术角度上都最接近实用要求的方案。这种燃料方案的主要问题是重整气中含有一定浓度的CO（通常为1-2％），CO会使低温燃料电池（低于100℃操作）的阳极催化剂中毒，导致电池性能大幅下降。因此解决PEMFC的CO问题对PEMFC技术的发展应用具有重要意义。 本论文发展了一种改进的浸渍还原法用以制备具有良好抗CO能力的高活性PtRu／C电催化剂，通过低级醇作为表面活性剂降低催化剂颗粒在载体上沉积还原过程中的生长作用，保证了催化剂具有高分散度，从而保证了它的活性；通过对碳载体孔结构对电催化剂分散度的影响的研究，认为电催化剂的理想碳载体应具备高的比表面积和以中孔结构为主的孔结构，并提出通过改进电催化剂载体的结构和组成实现提高电催化剂活性和功能的思路；根据修饰载体的观点，我们制备了含有过渡金属氧化物（HxMeO₃／C，Me=W或Mo）的复合载体，采用所发展的浸渍还原法成功地制备了三组分抗CO催化剂PtRu-H_xMeO₃／C，该催化剂保持了与PtRu／C相当的分散度，并且由于燃料在过渡金属氧化物的溢流氧化作用，使得电催化剂的抗CO能力得到了进一步的提高；最后我们发展了一种以电化学氧化为基本作用的抗CO复合阳极结构，指出其关键因素是在催化层中实现不同催化剂的梯度分布，并实现了两种具有良好抗CO性能复合阳极结构的制备方法。更多还原

【Abstract】 The selection of the fuel is a key problem for the development and the application of proton exchange membrane fuel cells (PEMFCs), and the fuel produced by the reforming of methanol, gasoline or natural gas should be the most proper candidate for the mature reforming technology and the availability of the carbon containing fuels. However, the component of CO in the reforming gas (1-2%) is a severe poison to the anode electrocatalyst of PEMFCs, and the cell performance would decease seriously due to the CO poisoning of the anode electrocatalysts. Therefore, to solve the CO problem of PEMFC is crucial for the development and application of PEMFCs.A modified impregnating method for preparing highly dispersed PtRu/C electrocatalyst with an enhanced CO tolerance was developed in this thesis, which was characterized with the employment of alcohols as the surface active agent to lower the conglomerating inclination of the catalyst particles during their forming processes. The effect of the pore structure of the carbon support on the dispersion of the catalyst was investigated. It is found that the most proper structure should be of high surface area and the meso-pore distribution. At the same time it was brought forward that the enhancement of the activity and the function of the electrocatalyst could be achieved by modifying the structure and the component of the supports. According to modifying the carbon support with an additional component of the transitional metal oxide, e.g. HxMeO3/C (Me=W or Mo), the CO tolerant electrocatalysts of PtRu-HxMeO3/C were prepared through the modified impregnating method. The catalysts of PtRu-HxMeOs/C kept similar dispersion withthe PtRu/C and showed higher CO tolerance than the PtRu/C due to the spill-over effect of the fuels on the composite support. Except for the CO tolerant electrocatalysts, we have developed a novel kind of CO tolerant anode with a composite catalyst layer structure based on the electrooxidation mechanism. It was pointed out that the key factor for the achievement of CO tolerance was to acquire a proper distribution of the different catalysts in the anode. According to the above view, two kinds of the composite anode were developed with an enhanced CO tolerance in comparison with the traditional electrode.更多还原