Comparison of Alcohol Electrooxidation on Platinum Monolayers in Alkaline Media

Abstract

This research was performed to better understand the performance of Platinum and Palladium electrodes in direct alcohol fuel cells. In the experiment, a variety of catalysts [polycrystalline Pt, polycrystalline Pd, Pt(111), Pd(111) and PtML/Pd(111)] were tested in a variety of alcohol fuels (methanol, ethanol, npropanol, isopropanol, ethylene glycol and glycerol). Performance of the various catalyst and fuel combinations indicated that certain fuels performed more optimally on specific catalysts. For the polycrystalline electrodes, Pt showed optimal activity with glycerol and Pd demonstrated optimal activity with methanol, ethanol and n-propanol. For both single crystal electrodes, Pt(111) and Pd(111) optimal activity was with ethanol and n-propanol. In the PtML/Pd(111) electrode, overall activity for all fuels was low; however, the highest activity fuels were glycerol, ethanol and n-propanol. As expected PtML/Pd(111) behaved in a similar way to Pt(111) although overall peak activity levels were lower than that of the bulk electrode. For application purposes, it would be necessary to explore the trade-offs between cost, performance and stability.