Study of the variation of catalyst loading in cathode for SPEEK/CSMM membrane in direct methanol fuel cell (DMFC)

Abstract

Variation of anode catalyst loading for modified sulfonated poly (ether ether ketone) (SPEEK) with charged surface modifying macromolecules (cSMM) membrane was studied, in order to get the higher performance in DMFC. The best optimal anode catalyst loading was 4 mgcm-2 for 30% Pt/Ru based on our previous result for this application. The modified SPEEK/CSMM membrane was characterized to ensure of its better performance in term of water uptake and methanol permeability. In cathode side, the effect of 5% and 10% Pd/C in 2,4 and 6 mgcm-2 of catalyst loading has been investigated with a fuel cell assembly. The preparation method of catalyst ink and membrane electrode assembly (MEA) was based on Dr. Blade method and hot pressing by using catalyzed diffusion media (CDM) method. The air flowrates were varied from 25-1000ml min-1, while 1M methanol concentrations, 1 ml min-1 of methanol flowrate and 60°C operating temperature were kept constant. These parameters were tested on the performance of single cell DMFC with 4 cm2 electrodes.The optimization catalyst loading will enhance the DMFC performance. It was found, the best optimal cathode catalyst loading was 4 mgcm-2 for 10% Pd/C with 4 mgcm-2 for 30% Pt/Ru in anode side for this application.