导　　师： 潘牧;徐东升

学科专业： H0502

授予学位： 硕士

作　　者： ;

机构地区： 武汉理工大学

摘　　要： 质子交换膜燃料电池/(PEMFC/)普遍采用Pt//C作为电催化剂,但是Pt资源稀少且其造价高,阻碍了燃料电池的发展。因为碳载体的腐蚀,会导致Pt//C催化剂失活。同时由于Pt//C中大尺寸的碳载体增加了催化层的厚度,从而影响电极反应各相传质的速度以及其反应速度。为了提高了催化剂性能,优化催化剂结构是必要的。本文选择模板法制备Pt纳米阵列/(PtNWs/)催化剂,首先采用阳极氧化制备不同尺寸的阳极氧化铝/(AAO/)模板,然后利用AAO模板电沉积制备出不同尺寸的Pt纳米阵列,将其作为燃料电池催化剂,对该催化剂进行了XPS, SEM、TEM>、ICP-AES以及电化学测试,研究结果表明： /(1/)溶解AAO模板后,制备的Pt NWs形状是比较规则的圆柱形,很好的复型了AAO模板的均匀孔道。Pt NWs的直立情况良好,这样自支撑的结构将有利于催化剂的电化学测试。 /(2/)根据Pt NWs循环伏安曲线中氢吸附脱附电量和CO氧化电量计算出,Pt NWs的电化学活性面积远远大于几何面积。 /(3/)根据旋转圆盘电极/(ROE/)测试的Pt NWs催化剂的ORR曲线中,Pt NWs的半波电势相对于Pt//C有正移,且Pt NWs的极限扩散电流比Pt//C要大。 /(4/)催化剂的甲醇氧化曲线中,Pt NWs的甲醇氧化峰电流比Pt//C大,这说明Pt NWs的甲醇催化氧化性能比Pt//C好。三种尺寸的Pt NWs甲醇氧化峰电位较Pt//C都有正移,其中25nmPt NWs的峰位与Pt//C最接近,这说明Pt纳米线尺寸越小,越有利于甲醇的催化氧化。 In the electrode of PEMFC, Pt//C catalyst is most commonly used. For the lack of Pt material and its high cost in the world, commercial application of PEMFC faces barriers. Because of the carbon corrosion, the catalyst would lead to deactivation. And also, large-size carbon support increases the thickness of the catalyst layer, thus affecting the rate of mass transfer and electrode reaction speed. In order to improve the catalyst performance, it is necessary to optimize the structure of catalyst. In this paper, platinum nanowire arrays were fabricated by electrodepositing, utilizing nanochannel alumina templates, then used it as the catalyst of PEMFC. First we prepared different size aluminum templates by anodic oxidation, then electrodeposited Pt as catalyst. X-ray photoelectron spectroscopy/(XPS/), scanning electron microscope/(SEM/), transmission electron microscopy/(TEM/), inductively coupled plasma-atomic emission spectrometry/(ICP-AES/) and electrochemical measurement were used to characterize these catalysts. The results indicated that: /(1/) After dissolving AAO template, as-prepared Pt NWs are relatively regular cylindrical shape, and they are good replicas of the uniform pores of AAO templates. As Pt NWs are upright in good condition, their self-supporting structure will facilitate the electrochemical measurements. /(2/) According to the cyclic voltammetry curves of hydrogen adsorption and CO stripping for Pt NWs catalysts, it is seen that electrochemical surface area/(ECSA/) of Pt NWs was far greater than the geometric area. /(3/) The half wave potential in ORR curves of Pt NWs is more positive than Pt//C in RDE measurements. This shows that the oxygen reduction reaction carries out more easily for Pt NWs. Moreover, compared with the conventional Pt//C catalyst, Pt NWs catalysts present higher limiting diffusion current. It is because highly ordered Pt NWs provides a good set of mass transfer channel and serves as an excellent current collector. /(4/) The peak current in methanol oxidation curves of Pt NWs is greater than Pt//C, indicating better methanol electrooxidation of Pt NWs. The peak potential in methanol oxidation of three kinds of Pt NWs peak potential showed a positive shift compared with that of Pt//C. The peak potential of 25nmPt NWs is most closed to that of Pt//C, which shows that the smaller size of Pt NWs, the better the catalytic of methanol oxidation.

关 键 词： 质子交换膜燃料电池 模板 铂纳米阵列 氧还原 甲醇氧化

分 类 号： [TP2 TN1]

领　　域： [自动化与计算机技术] [自动化与计算机技术] [电子电信]