离子交换-电沉积法制备高Pt利用率多孔电极

采用离子交换-电沉积的方法(Ion-exchange/electrodeposition，IEE)制备了一种高Pt利用率催化电极，对所制备电极的表面形貌、催化活性及单电池性能用线性扫描伏安(LSV)、扫描电镜(SEM)、透射电镜(TEM)和单电池测试进行了表征. 结果表明，通过电极制备工艺和离子交换-电沉积参数的调控，能够消除碳载体表面官能团的影响，使铂阳离子只与全氟磺酸树脂(Nafion)上的H⁺进行交换. 在无铂离子的电解质中，将被交换的铂阳离子还原到与Nafion接触的碳载体上，使每一个铂纳米粒子都处于气体多孔电极的三相界面上，有效地调控铂纳米粒子的尺寸和分散度. 单电池测试表明，以铂载量为0.014 mgPt•cm^-2的IEE电极组装的电池的输出功率与铂载量为0.3 mgPt•cm-²的Nafion粘接Pt/C电极相当.

Porous Electrodes with High Pt Utilization Obtained by Ion-Exchange/Electrodeposition

We report a novel method based on ion-exchange/electrodeposition (IEE) for constructing high Pt utilization porous electrodes. The electrode prepared using IEE was assessed by linear sweep voltammetry (LSV), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and single cell test. The preliminary results show that the undesired ion-exchange between Pt anion and surface functional group in carbon black can be eliminated through the electrode preparation process, and every Pt particle prepared by IEE is expected to be deposited on the three-phase reaction zone and thus can be fully utilized in fuel cell reactions. The Pt particle size, shape and distribution obtained by IEE can be controlled by modulating the IEE technique and cycles. The power output of the MEA employing a Pt/C electrode prepared by IEE with a Pt loading of 0.014 mgPt•cm^-2 is equivalent to that employing a conventional Nafion-bonded Pt/C electrode with a Pt loading of 0.3 mgPt•cm^-2.