高温质子交换膜燃料电池的复合催化层电极

高温质子交换膜燃料电池具有耐毒化,稳定性好的优势,是具有较强应用前景的一种能源转换装置。 本文制备了具有复合催化层结构的气体扩散电极,用于增强燃料电池阳极的催化性能。 在气体扩散电极中,将偏氟乙烯-六氟丙烯共聚物和聚苯基咪唑聚合物作为催化剂的粘结材料,调节了电极界面的浸润结构。 通过对电极表面形貌和润湿性的表征,发现该种结构的催化层孔隙率和粗糙度更高,双层结构的润湿性差别明显(接触角分别为149°和19°),这有利于形成稳定的三相反应界面。 测试结果表明,该种结构的催化层能够有效提高催化材料的利用效率,燃料电池对氢气燃料的峰值功率密度提高约22%。 与此同时,使用含一氧化碳质量浓度为10000和30000 mg/m³的氢气燃料,电池峰值功率密度能够分别保持82.1%和71.4%,证明该燃料电池对一氧化碳杂质保持了良好的耐毒性。

Multilayered Anode Catalytic Electrode in High-Temperature Proton Exchange Membrane Fuel Cell

High temperature proton exchange membrane fuel cell is a promising energy conversion device with the advantages of toxicity resistance and good stability. In this report, the multilayered catalytic structure was designed to improve anode electrode catalytic activity of fuel cell. Poly vinylidene fluoride co-hexafluoropropylene(PVDF-HFP) and polybenzimidazoles(PBI) are used as electrode binders to adjust the wettability of the diffusion electrode interface. The surface morphology and wettability of the electrode catalyst have been characterized. It was found that the porosity and roughness of the electrode layer were improved. The wettability distinction between layers(contact angles:149° for PVDF-HFP and 19° for PBI) was conducive to produce more stable three-phase reaction interfaces. The catalytic performance of fuel cells shows that the peak power density is enhanced by about 22%, and it has retained 82.1% and 71.4% in H₂ fuel containing CO at the concentrations of 10000 mg/m³ and 30000 mg/m³, respectively. It is concluded that the catalytic layer with such structure could increase the catalyst utilization and still maintain good toxic resistance to CO impurity inside fuel gas.