Pingwen Ming

Comparative Study of PEM Fuel Cell Storage at − 20 ° C after Gas Purging

The effect of water removal and freeze/thaw cycles on proton exchange membrane (PEM) fuel cells was investigated by comparative study of 20 on/off and freeze/thaw cycles after purging by reactant gas with relative humidity 58.0% at 25°C. Within 20 cycles, the cell performance, electrochemical active surface areas, and electrochemical impedance spectra responses were analyzed by the mean squared deviation method. No performance decay caused by water freezing was observed, and the water amount in the cell was reduced to an extent by which freeze degradation was avoided.

The oxidation resistance of tungsten carbide as catalyst support for proton exchange membrane fuel cells

Electrochemical oxidation of carbon supports for Pt/C catalysts can cause degradation of proton exchange membrane fuel cells (PEMFCs). To improve the oxidation resistance of the catalyst supports, tungsten carbide (WxCy) was investigated as a substitute for carbon supports in PEMFCs. The Pt/C and Pt/WxCy samples were oxidized using the chronoamperometry method. The electrochemical active area of the two samples was measured using cyclic voltammetry. Furthermore, the Pt/C and Pt/WxCy catalysts were applied to single cells to compare their performance degradation after oxidation. As a result, the single cell prepared with Pt/WxCy catalyst showed higher oxidation resistance than the contrastive cell prepared with Pt/C catalyst.