In this study, a research technique - Dynamic Electrochemical Impedance Spectroscopy for FUEL CELL research is presented. The DIRECT METHANOL FUEL CELL was the object of the study. The changes of operational conditions such as temperature, oxidant flow intensity and load on the CELL global impedance were examined. The results of these changes on the performance of the CELL were observed.

A two-dimensional, single-phase, isothermal model has been developed for a DIRECT METHANOL FUEL CELL (DMFC). The model considers the anode and cathode electrochemical equations, continuity, momentum and species transport in the entire FUEL CELL. Then, the equations are coupled together and solved simultaneously using a commercial, Finite element based, COMSOL Multiphysics software. The crossover of METHANOL is also investigated in the model. This model describes the electrochemical kinetics of METHANOL oxidation at the anode catalyst layer by nonTafel kinetics. The concentration distribution of METHANOL, water, and oxygen was predicted by the model. In addition, the changes of METHANOL crossover and FUEL utilization with current density were evaluated for different METHANOL concentrations (0. 5 M, 1 M, 2 M, 4 M, and 6 M). Furthermore, it was also found that the crossover of METHANOL decreases at low METHANOL concentrations and high current densities. The results show that the polarization curve is in agreement with experimental data.

The power density of a DIRECT METHANOL FUEL CELL (DMFC) stack as a function of temperature, METHANOL concentration, oxygen flow rate, and METHANOL flow rate was studied using a response surface methodology (RSM) to maximize the power density. The operating variables investigated experimentally include temperature (50-75 ° C), METHANOL concentration (0. 5-2 M), METHANOL flow rate (15-30 ml min-1), and oxygen flow rate (900-1800 ml min-1). A new design of the central composite design (CCD) for a wide range of operating variables that optimize the power density was obtained using a quadratic model. The optimum conditions that yield the highest maximum power density of 86. 45 mW cm-2 were provided using 3-CELL stack at a FUEL CELL temperature of 75 ° C with a METHANOL flow rate of 30 ml min-1, a METHANOL concentration of 0. 5 M, and an oxygen flow rate of 1800 ml min-1. Results showed that the power density of DMFC increased with an increase in the temperature and METHANOL flow rate. The experimental data were in good agreement with the model predictions, demonstrating that the regression model was useful in optimizing maximum power density from the independent operating variables of the FUEL CELL stack.

In this study, palladium nano-particles were electrodeposited galvanostatically on carbon black powder (Vulcan XC-72R). The catalytic activity for electro-oxidation of ethanol and METHANOL in alkaline media were studied by cyclic voltammetry and linear sweep voltammetry techniques. The results indicated that the electro-oxidation of ethanol and METHANOL strongly depends on adsorbed species on the electrocatalyst layer. Effects of ethanol, METHANOL and KOH concentration on the electrocatalytic properties of the synthesized electrocatalysts during electro-oxidation reactions were evaluated by linear sweep voltammetry with various scan rates. The overall rate equations for ethanol electro-oxidation and METHANOL electro-oxidation on Palladium /Vulcan in alkaline media were developed. It has been shown that the Pd-C particles with mass loading of 0. 11 mg cm – 2 have superior catalytic activity. Finally, two overall rate equations were developed for EOR and MOR.