聚苯胺对MnO_2空气电极性能影响的研究

Effect of polyaniline on air electrode properties

研究了添加聚苯胺对MnO2空气电极性能的影响,并考察了含聚苯胺的空气电极在不同电解液中的性能变化。结果表明,在5 mol/L的氯化铵电解液中,聚苯胺的加入可大幅度提高空气电极性能,并得到聚苯胺与MnO2催化剂的最佳质量配比为0.3∶1。分析认为,聚苯胺与氧分子间存在的顺磁相互作用,使得O2在催化层中的含量增大,阻止了MnO2催化剂因转变成MnOOH而失活。在0.9 mol/L氯化钠电解液中,聚苯胺的导电性能下降,导致电极欧姆极化增大,性能降低,但加入少量的全氟磺酸可改善电极性能。

The effect of adding polyaniline (PAn) on air electrode properties and the change of the electrode properties containing PAn in different electrolytes were investigated by measuring cathodic polarization curves. Results show that the addition of PAn can improve greatly the performance of the air electrode in 5 mol/L ammonium chloride electrolyte, and the best mass ratio between PAn and manganese dioxide catalyst in the catalytic layer is 0.3∶1. Analysis indicates that the concentration increase of oxygen in the catalytic layer is resulted by the paramagnetic interaction between PAn and O2, and the interaction can strengthen the transformation of Mn(Ⅲ) to Mn(Ⅳ). In 0.9 mol/L sodium chloride electrolyte, the performance of the air electrode containing PAn decreases with the decrease of the conductivity of PAn. But this can be improved by adding a small amount of perfluorosulfonate.