Catalyst layer
A catalyst layer comprising: (i) a platinum-containing electrocatalyst; (ii) oxygen evolution reaction electrocatalyst; (iii) one or more carbonaceous materials selected from the group consisting of graphite, nanofibres, nanotubes, nanographene platelets and low surface area, heat-treated carbon blacks wherein the one or more carbonaceous materials do not support the platinum-containing electrocatalyst; and (iv) proton-conducting polymer and its use in an electrochemical device is disclosed.
1. A catalyst layer comprising:
(i) a platinum-containing electrocatalyst;
(ii) an oxygen evolution reaction electrocatalyst;
(iii) carbonaceous material comprising a heat-treated carbon black having a surface area of less than 100 m 2 /g; and
(iv) a proton-conducting polymer;
wherein the carbonaceous material is dispersed within the platinum-containing electrocatalyst;
wherein the platinum-containing electrocatalyst is unsupported, supported on a non-carbonaceous support or supported on the oxygen evolution reaction electrocatalyst;
wherein the layer does not include a platinum-containing electrocatalyst supported on a carbonaceous support;
wherein the catalyst layer has a thickness of less than or equal to 20 μm; and,
wherein the ratio by weight of the platinum in the platinum-containing electrocatalyst to carbonaceous material is from 40:60 to 95:5.
2. The catalyst layer according to claim 1 , wherein the platinum-containing electrocatalyst is unsupported.
3. The catalyst layer according to claim 1 , wherein the carbonaceous material does not support the oxygen evolution catalyst.
4. The catalyst layer according to claim 1 , wherein the catalyst layer is ≥1 μm in thickness.
5. The catalyst layer according to claim 1 , wherein the loading of platinum is ≤0.8 mg/cm 2 .
6. The catalyst layer according to claim 1 , wherein the loading of platinum is ≥0.01 mg/cm 2 .
7. An electrode comprising a gas diffusion layer and the catalyst layer according to claim 1 .
8. The electrode according to claim 7 , wherein the electrode is an anode.
9. A catalyst-coated membrane comprising a proton-conductive membrane and the catalyst layer according to claim 1 .
10. A membrane electrode assembly comprising the catalyst layer according to claim 1 .
11. A membrane electrode assembly comprising the electrode according to claim 7 .
12. A membrane electrode assembly comprising the catalyst-coated membrane according to claim 9 .
13. A membrane electrode assembly comprising the electrode according to claim 8 .