Electrodeposited PtCo and PtMn electrocatalysts for methanol and ethanol electrooxidation of direct alcohol fuel cells

PtCo and PtMn electrocatalyst particles were successfully synthesized on Ti substrate by the electrode-postion method. PtCo particles deposited are star-shaped particles with size of 100-200 nm and very porous with many slices of similar to 10nm. On the other hand, PtMn particles are spherical and have no obvious conglomeration, and the particle is in the range of 100-200nm. The results reveal that the effect of the incorporation of Co and Mn on the electrochemical active surface area of Pt nanoaprticles is very small. However, incorporation of trace Co and Mn in Pt (e.g., Pt1000Co and Pt1000Mn) has dramatic effect on the electrochemical oxidation reaction of alcohol. The mass specific peak current for the methanol oxidation in alkaline media is 49 mA cm(-2) and 39 mA cm(-2) on Pt10000Mn and Pt1000Co, which is three and two times higher, respectively, than that on pure Pt electrocatalyst nanoparticles. PtMn and PtCo electrocatalysts also show significant enhanced stability for methanol oxidation. However, the electrocatalytic enhancement of Co or Mn to Pt is relatively small for the electrooxidation reactions of ethanol in alkaline media. (c) 2009 Elsevier Ltd. All rights reserved.