An oxidation-resistant indium tin oxide catalyst support for proton exchange membrane fuel cells
An oxidation-resistant indium tin oxide catalyst support for proton exchange membrane fuel cells
复制标题
DOI：
10.1016/j.jpowsour.2006.05.014
复制
发表时间：
2006-10-27
影响因子：
9.2
通讯作者：
Kesler, O.
中科院分区：
文献类型：
--
作者：
Chhina, H.;Campbell, S.;Kesler, O.
在质子交换膜燃料电池(PEMFCs)中，碳催化剂载体的氧化会导致催化剂性能下降。氧化铟锡(ITO)被认为是一种可替代的催化剂载体。用旋转圆盘电极(RDE)研究了ITO的电化学稳定性。在+0.6~+1.8V之间的氧化循环用于负载铂催化剂的ITO。获得了在ITO、Hispec 4000(一种商用催化剂)上和在Vulcan XC-72R上内部分散的40wt.%铂在氧化循环前后的循环伏安图(CV)。铂在ITO上表现出更好的电化学稳定性，这是由循环后电化学活性表面积的相对变化决定的。对于ITO上的铂，即使在0.6~1.8V的100次循环后，CVS中仍存在氢的脱附峰。另一方面，Hispec 4000催化剂在100次循环后，大部分活性表面积都消失了。火神内部制造的40wt.%铂也在仅50次循环后失去了大部分活性区域。ITO上的铂比Hispec 4000和Vulcan XC-72R上的铂更稳定。研究发现，ITO表面的铂平均尺寸为13 nm，ITO为38 nm。ITO上的PT表现出极高的热稳定性，当加热到1000℃时，ITO的材料损失率仅为1wt.%，而Hispec 4000的材料损失率为57wt.%。扫描电子显微镜数据表明，八面体形状的ITO颗粒负载着铂。(C)2006年，爱思唯尔出版。
The oxidation of carbon catalyst supports causes degradation in catalyst performance in proton exchange membrane fuel cells (PEMFCs). Indium tin oxide (ITO) is considered as a candidate for an alternative catalyst support. The electrochemical stability of ITO was studied by use of a rotating disk electrode (RDE). Oxidation cycles between +0.6 and +1.8 V were applied to ITO supporting a Pt catalyst. Cyclic voltammograms (CVs) both before and after the oxidation cycles were obtained for Pt on ITO, Hispec 4000 (a commercially available catalyst), and 40 wt.% Pt dispersed in-house on Vulcan XC-72R. Pt on ITO showed significantly better electrochemical stability, as determined by the relative change in electrochemically active surface area after cycling. Hydrogen desorption peaks in the CVs existed even after 100 cycles from 0.6 to 1.8 V for Pt on ITO. On the other hand, most of the active surface area was lost after 100 cycles of the Hispec 4000 catalyst. The 40 wt.% Pt on Vulcan made in-house also lost most of its active area after only 50 cycles. Pt on ITO was significantly more electrochemically stable than both Hispec 4000 and Pt on Vulcan XC-72R. In this study, it was found that the Pt on ITO had average crystallite sizes of 13 nm for Pt and 38 nm for ITO. Pt on ITO showed extremely high thermal stability, with only similar to 1 wt.% loss of material for ITO versus similar to 57 wt.% for Hispec 4000 on heating to 1000 degrees C. The TEM data show Pt clusters dispersed on small crystalline ITO particles. The SEM data show octahedral shaped ITO particles supporting Pt. (c) 2006 Published by Elsevier B.V.