Investigation of the Effects of Catalyst Loading and Gas Flow Rate on Polymer Electrolyte Membrane (Pem) Fuel Cell Performance and Degradation
In this paper, the effects of gas flow rates and catalyst loading on polymer electrolyte membrane fuel cell (PEMFC) performance was investigated using a 50 cm2 active area fuel cell fixture with serpentine flow field channels machined into poco graphite blocks. Membrane electrode assemblies (MEAs) with catalyst and gas flow rates at two levels each (0.5 mg/cm2 , 1 mg/cm2 ; 0.3 l/min, 0.5 l/min, respectively) were tested at 60?°C without humidification. The cell performance was analyzed by taking ac impedance, Tafel plot, open circuit voltage, and area specific resistance measurements. It was observed that MEAs with lower gas flow rate had lesser cell resistance compared to MEAs with a higher gas flow rate. Tafel plot shows the highest exchange current density value of 10? 2.05 mA cm2 for MEA with 0.5 mg/cm2 catalyst loading tested at reactant gas flow rate of 0.3 l/min signifying it had the least activation loss and fastest reaction rate. Open circuit voltage-time curve shows a higher output voltage and lesser voltage decay rate for MEAs tested at higher gas flow rates.
A. C. Okafor and H. C. Mogbo, "Investigation of the Effects of Catalyst Loading and Gas Flow Rate on Polymer Electrolyte Membrane (Pem) Fuel Cell Performance and Degradation," Journal of Fuel Cell Science and Technology, American Society of Mechanical Engineers (ASME), Jan 2011.
The definitive version is available at http://dx.doi.org/10.1115/1.4005120
Mechanical and Aerospace Engineering
Keywords and Phrases
Electrical Resistance; Impedance (Electricity); Gas Flow; Fuel Cells; Catalysts; Circuits; Electrical Potential; Proton Exchange Membrane Fuel Cells; Electrodes; Flow (Dynamics)
Article - Journal
© 2011 American Society of Mechanical Engineers (ASME), All rights reserved.