The performance of flow field channel in direct methanol fuel cell

A 3D computational fluid dynamics (CFD) model is developed to examine the impact of flow field design on the performance of direct methanol fuel cells (DMFCs). Effect of three various type flow fields is investigated in this study: single, double serpentine and honeycomb models. The distribution of velocity and temperature are simulated in 3D models. According to simulation studies, the honeycomb flow field has made uniform flow velocity distribution and minimum temperature change on plate surface. This could result better on DMFC performance. The experimental studies emphasize the performance of a single cell DMFC with different flow field channel designs as well as exhibit maximum power density and open circuit voltage. In subsequent study, electrodeposited Ni-Co alloy on stainless steel mesh surface is utilized to oxidize methanol and the electrode performance has been tested using cyclic voltammetry in alkaline conditions to replace expensive and sensitive platinum and platinum alloy catalysts

Intermediate Temperature Fuel Cell and Oxygen Reduction Studies With Carbon-Supported Platinum Alloy Catalysts in Phosphoric Acid Based Systems

The oxygen reduction activities of platinum and platinum alloy catalysts were evaluated at temperatures up to 150 °C in phosphoric acid solution. The oxygen reduction currents and open circuit potentials were measured using chronoamperometry with double potential steps to eliminate the effects of double layer charging currents and metal deactivationcould be eliminated effectively. Based on the mass activity at 0.7 V versus Ag/AgCl, the commercial PtNi catalyst showed higher performances than commercial Pt catalyst at 150 °C. The commercial PtCo catalyst showed high activities at 90 °C and 120 °C. Intermediate temperature fuel cells based on phosphoric acid doped polybenzimidazole membranes were tested with the alloy cathode catalysts. In the case of Pt–Fe alloy an enhanced performance was achieved in comparison to that with Pt carbon catalysts.