甘油对聚苯并咪唑基膜电极结构和性能的影响

Influence of Glycerol on the Structure and Performance of PBI Based Membrane Electrode Assemblies

为使膜电极发挥最佳性能,一般需要对其进行活化,而膜电极的孔结构往往对活化起到关键性作用。通过在催化剂浆料中添加不同含量的甘油,制备了不同孔结构的膜电极,并考察了甘油含量对聚苯并咪唑(PBI)基膜电极的结构和性能的影响。结果表明:随着甘油含量增加,100μm左右的大孔含量随之增加,气体扩散电极表面接触角依次降低;膜电极性能达到平稳所需的时间越短,活化前后膜电极性能提升的幅度越小;当甘油含量进一步提升至3.0 mg/cm^(2)时,膜电极的性能却出现了明显的下降,最佳甘油含量为1.5 mg/cm^(2)。

In order to maximize the performance of membrane electrode assembly(MEA),it is necessary to activate it.The pore structure of MEA often plays a key role to activation.In this paper,the MEAs with different pore structure was prepared by adding different content of glycerol into catalyst slurry,and the effect of glycerol content on the structure and performance of PBI based MEAs was investigated.The results showed that,with the increase of glycerol content,the macropore content of about 100μm increased,and the surface contact angle of GDE decreased in turn.The shorter the time reguired for the performance of MEA to reach stability,the smaller the improvement of MEA performance before and after activation.However,when the glycerol content increased to 3.0 mg/cm^(2),the performance of the MEA decreased significantly.The optimum glycerol content was 1.5 mg/cm^(2).