A membrane electrode assembly adapted for use in a fuel cell, the membrane electrode assembly comprising, in order: a first gas distribution layer; optionally a first gas dispersion layer; an anode catalyst layer comprising a first catalyst, said first catalyst being a hydrogen oxidation reaction catalyst; a membrane; a cathode catalyst layer comprising a second catalyst, said second catalyst being an oxygen reduction reaction catalyst; optionally a second gas dispersion layer; and a second gas distribution layer, wherein the first gas distribution layer has first and second generally opposed major surfaces (101, 102); wherein the anode catalyst layer has first and second generally opposed major surfaces (301, 302), wherein the second major surface of the first gas distribution layer is closer to the first major surface of the anode catalyst layer than to the second major surface of the anode catalyst layer; wherein the membrane has first and second generally opposed major surfaces (401, 402), wherein the second major surface of the anode catalyst layer is closer to the first major surface of the membrane than to the second major surface of the membrane; wherein the cathode catalyst layer has first and second generally opposed major surfaces (501, 502), wherein the second major surface of the membrane is closer to the first major surface of the cathode catalyst layer than to the second major surface of the cathode catalyst layer; and wherein the second gas distribution layer has first and second generally opposed major surfaces (701, 702), wherein the second major surface of the cathode catalyst layer is closer to the first major surface of the second gas distribution layer than to the second major surface of the second gas distribution layer, characterised in that at least one of the following applies: a layer comprising oxygen evolution reaction catalyst is disposed on the first major surface of the first gas distribution layer; the first gas distribution layer comprises oxygen evolution reaction catalyst; the optional first gas dispersion layer is present and a layer comprising oxygen evolution reaction catalyst is disposed between the first gas distribution layer and the first gas dispersion layer; the optional first gas dispersion layer is present and a layer comprising oxygen evolution reaction catalyst is disposed on the first major surface of the first gas dispersion layer; the optional first gas dispersion layer is present and the first gas dispersion layer comprises oxygen evolution reaction catalyst; the optional second gas dispersion layer is present and the second gas dispersion layer comprises oxygen evolution reaction catalyst; the optional second gas dispersion layer is present and a layer comprising oxygen evolution reaction catalyst is disposed on the second major surface of the second gas dispersion layer; the optional second gas dispersion layer is present and a layer comprising oxygen evolution reaction catalyst is disposed between the second gas distribution layer and the second gas dispersion layer; the second gas distribution layer comprises oxygen evolution reaction catalyst; and a layer comprising oxygen evolution reaction catalyst is disposed on the second major surface of the second gas distribution layer. a first gas distribution layer; optionally a first gas dispersion layer; an anode catalyst layer comprising a first catalyst, said first catalyst being a hydrogen oxidation reaction catalyst; a membrane; a cathode catalyst layer comprising a second catalyst, said second catalyst being an oxygen reduction reaction catalyst; optionally a second gas dispersion layer; and a second gas distribution layer, a layer comprising oxygen evolution reaction catalyst is disposed on the first major surface of the first gas distribution layer; the first gas distribution layer comprises oxygen evolution reaction catalyst; the optional first gas dispersion layer is present and a layer comprising oxygen evolution reaction catalyst is disposed between the first gas distribution layer and the first gas dispersion layer; the optional first gas dispersion layer is present and a layer comprising oxygen evolution reaction catalyst is disposed on the first major surface of the first gas dispersion layer; the optional first gas dispersion layer is present and the first gas dispersion layer comprises oxygen evolution reaction catalyst; the optional second gas dispersion layer is present and the second gas dispersion layer comprises oxygen evolution reaction catalyst; the optional second gas dispersion layer is present and a layer comprising oxygen evolution reaction catalyst is disposed on the second major surface of the second gas dispersion layer; the optional second gas dispersion layer is present and a layer comprising oxygen evolution reaction catalyst is disposed between the second gas distribution layer and the second gas dispersion layer; the second gas distribution layer comprises oxygen evolution reaction catalyst; and a layer comprising oxygen evolution reaction catalyst is disposed on the second major surface of the second gas distribution layer.