A one-dimensional model of a direct methanol fuel cell anode with a novel double-layer structured MEA

A direct methanol fuel cell (DMFC) with a novel double-layer structured membrane electrode assembly (MEA) was developed and a better performance was obtained. The double catalytic layer anode is composed of a hydrophilic inner catalyst layer with PtRu black and an outer catalyst layer with PtRu/C. In the double-layer structured anode, there existed a catalyst concentration gradient and porosity gradient, resulting in good mass transfer, proton and electron conducting. Furthermore, the delamination of the catalyst layer from the membrane was also resolved because of the inner hydrophilic catalyst film. To optimize the combination of the two catalysts layer a one-dimensional model based on Tafel type kinetics and semi-empirical mass transport coefficient was applied. The simulation of anode overpotential versus PtRu Blk inner layer thickness and PtRu/C outer layer thickness results showed a direct methanol fuel cell with a 5 mum thick inner PtRu black catalyst layer and an 8 mum thick outer 40 wt%PtRu/C catalyst layer as anode electrode was the best.