Optimization of properties and operating of a passive DMFC mini-stack at ambient temperature

An investigation of properties and operating parameters of a passive DMFC monopolar mini-stack, such as catalyst loading and methanol concentration, was carried out. From this analysis, it was derived that a proper Pt loading is necessary to achieve the best compromise between electrode thickness and number of catalytic sites for the anode and cathode reactions to occur at suitable rates. Methanol concentrations ranging from 1M up to 10M and an air-breathing operation mode were investigated. A maximum power of 225mW was obtained at ambient conditions for a three-cell stack, with an active single cell area of 4cm2, corresponding to a power density of about 20mWcm-2.