Direct catalyst coating on free standing microporous layer
Methods of making reinforced membrane electrode assemblies are described. Catalyst coated free standing microporous layers and reinforced membrane electrode assemblies are also described.
1. A method of making a reinforced membrane electrode assembly comprising:
placing a shim frame on a free standing microporous layer;
applying a catalyst coating to the shim frame such that the catalyst coating covers the free standing microporous layer to form a catalyst coated free standing microporous layer;
drying the catalyst coated free standing microporous layer;
providing a polymer membrane; and
bonding the catalyst coated free standing microporous layer on a surface of the polymer membrane.
2. The method of claim 1 wherein the catalyst coated free standing microporous layer is bonded using a hot press process.
3. The method of claim 1 further comprising inserting a subgasket material between the catalyst coated free standing microporous layer and the polymer membrane before bonding.
4. The method of claim 1 wherein a second catalyst coated free standing microporous layer is bonded on a second surface of the polymer membrane.
5. The method of claim 1 wherein the catalyst coating further comprises at least one of an ionomer, and carbon nanofiber.
6. The method of claim 1 wherein at least two layers of catalyst are coated on the free standing microporous layer.
7. The method of claim 1 wherein the layer of catalyst further comprises at least one of an ionomer, and carbon nanofiber.
8. The method of claim 1 wherein
the applying comprises sliding a sliding bar or brush through the catalyst coating.
9. The method of claim 8 wherein the coating material is placed on the shim frame without the catalyst coating contacting the free standing microporous layer.
10. The method of claim 8 further comprising applying a vacuum to the free standing microporous layer.