Enhancement of CO Tolerance on Electrodeposited Pt Anode for Micro-PEM Fuel Cells

Abstract

Electrodeposited and sprayed Pt anode catalysts were electrochemically characterised by CO stripping voltammetry as well as their activity to CO tolerance in micro-PEMFCs was demonstrated using polarisation measurements. While the onset and peak potentials of CO oxidation on the sprayed Pt/C varied with the CO coverage, these were lower (similar to 50 mV) with the electrodeposited Pt anode. This difference is attributed to the varying properties of the Pt-OH on either rough or smooth surface mainly created from different sizes of Pt particles. In fuel cell performance test, the electrode-posited Pt anode showed maximum power density of 360 mW cm(-2) and it was markedly (similar to 110 mW cm(-2)) higher than the sprayed Pt/C anode. The enhanced activity of the electrodeposited Pt anode is also reflected by the fact that the entire amount of adsorbed CO becomes almost desorbed during the first three polarisation scans, while with the Pt/C anode at least five cycles are required.