Optimization of Direct 2-propanol Fuel Cell Performance Using Statistical Design of Experiments Approach

Direct alcohol fuel cells have been attracting enormous research interest as power sources for vehicles and portable electronic devices because alcohols are readily available, their storage and transport can be easily handled with the existing fuel infrastructure, and they commonly have high mass-specific and volumetric energy densities. Methanol is the most studied fuel for direct alcohol fuel cells because methanol is readily available, it is structurally simple, and has a promising electrochemical activity. However, several research groups have also reported the use of 2-propanol as a promising fuel. The potential advantages of utilizing 2-propanol as fuel are many such as it is relatively less toxic compared to other alcohols, at low potentials it is less prone to anode poisoning, and it has better resistance to crossover and cathode poisoning. The performance of the fuel cell for a particular catalyst system is related to the cell conditions such as 2-propanol concentration, anode and cathode fuel flow rates, cell temperature and oxidant back pressure. This study was designed to study the effect of the different cell operation conditions at three different levels and the interactions between these components by response surface methodology (RSM). We observed that the power density of the cell increased with increase in molar concentration of 2-propanol and cell operation temperature, the optimized conditions for the highest power density of 45 mW/cm 2 by the RSM was found to be 1.5 M 2-propanol concentration, 80 o C cell temperature, 9.22 ml/min 2-propanol flow rate, 596 ml/min oxygen flow rate and no back pressure for the oxidant, this is from amongst one of the best results reported in literature for direct 2-propanol fuel cell performance.