Ink的状态对微型PEMFC氧电极Pt利用率的影响

Influence of Ink configurations on Pt utilization of micro-PEMFC's oxygen electrode

电化学极化实验表明,Ink(催化剂与溶剂在超声条件下形成的墨水状浆料)为胶体时,对应的微型质子交换膜燃料电池(PEMFC)氧电极极化性能相对于Ink为溶液时有明显提高。通过激光粒度实验和扫描电镜实验证实了Ink不同状态时对应的氧电极催化层空间状态和厚度存在较大差异。Ink为胶体时催化层Pt簇团聚粒子间隙较大,催化层厚度较低,有利于氧电极的反应传质过程,这是氧电极性能提高的根本原因。循环伏安实验结果发现,Ink为胶体时对应的氧电极Pt的利用率从25.2%提高到31.6%。

In this paper, influence of different Ink configurations on Pt utilization of micro- PEMFC＇ s oxygen electrode was determined by experiments of electrochemistry polarization（EP）, laser particles（LP） and scan electronic microscope （SEM）. The results suggested that the catalyst layer of oxygen electrode made from colloidal ink has larger Pt agglomerates against that of solution ink. Thus, the clearance between the agglomerates intends to increase, which facilitates mass transport inside of oxygen electrode. Meanwhile, the bigger agglomerates seem to reduce the possibility of Pt particles＇ penetration deep into the diffusion layer. The above gives the final explanations of electrochemical polarization performance improvement of oxygen electrode.