NH_3杂质对HT-PEM燃料电池性能的影响

Effects of the Ammonia Impurity on Performance of the HT-PEMFuel Cell

目的研究氢燃料中存在NH3杂质时对高温质子交换膜燃料电池的影响.方法使用燃料电池测试系统测试了HT-PEM燃料电池的极化曲线和交流阻抗图谱,采用等效电路法获得了HT-PEM燃料电池的等效电路元件,并对被NH3毒化后的电池催化剂层进行了电子显微扫描,分析了氢燃料中NH3质量浓度、电池温度和使用时间对HT-PEM燃料电池性能的影响.结果氢燃料中NH3的存在改变了电池电极电化学反应界面的结构,阻碍了质子的传递,导致电池性能下降,并且被NH3毒化后HT-PEM燃料电池再通入纯净氢气后电池性能仍继续下降.结论氢燃料中的NH3对HT-PEM燃料电池有很强的毒化作用,主要体现在降低了电池电极电化学反应界面,同时,被NH3毒化后HT-PEM燃料电池性能很难恢复,这种损害是不可逆的.

The purpose of this paper is to study effects of NH3 as fuel impurity on performance of the high temperature proton exchange membrane (HT-PEM)fuel cell. Polarization curves and AC impedances of the HT-PEM fuel cell were tested by fuel cell test system. The equivalent circuit method was used to obtain the equivalent circuit element, and cell catalyst layers after NH3 poison- ing were scanned with the electron microscope. Effects of NH3 density, fuel cell temperature and u- sing time on the cell performance were analyzed. It is observed that NH3 in hydrogen fuel changes the structure of fuel cell electrode electrochemical reaction interface ,hinders proton transfer ,leads to performance decline of the HT-PEM fuel cell. And after NH3 poisoning, the performance of the cell injected pure hydrogen also is decreased. Conclusion is that the performance of the HT-PEM fuel cell that is poisoned by the NH3 impurity is difficult to be restored. The damage is irreversible.