Th. Lim

Gradient Catalyst Coating for a Proton Exchange Membrane Fuel Cell Operation under Nonhumidified Conditions

Operation under nonhumidified conditions was demonstrated with a membrane electrode assembly (MEA) for a proton exchange membrane fuel cell. The Pt catalyst was coated with a gradient on the active area of a MEA; the catalyst amount was reduced gradually from cathode inlet to outlet. The MEA with the gradient coating method produced more water near the inlet site than that with the uniform coating method. The water was used to mitigate dryness of the MEA. The cell performance was improved by 17% at 800 mA/cm 2 under nonhumidified conditions by effective water management of the gradient coating method.

Novel Membrane Electrode Assembly (MEA) Fabrication for PEMFC Operations under Non-humidified Conditions

The operation under non-humidified condition was demonstrated with novel MEA (membrane electrode assembly) for a PEMFC (proton exchange membrane fuel cell). For a conventional PEMFC operation, Pt is loaded uniformly on the whole active area of MEA. In the report, Pt catalyst was coated with a gradient on the active area of MEA. The catalyst amount was reduced gradually from cathode inlet to outlet. When the cell was fully humidified, the performance of gradient catalyst coated MEA was lower than that of the uniform catalyst coated one. However, when the cell was operated under non-humidified condition, the cell performance of the gradient catalyst coated MEA was higher than that of the uniform catalyst coated MEA. In the case of the gradient catalyst coated electrode, the amount of water which was generated at the cathode inlet site was relatively large compared to uniform catalyst coated one and the water was used to hydrate the MEA properly, resulting in higher cell performance under non-humidified condition.