An electrocatalyst ink comprising one or more electrocatalyst metals and one or more proton-conducting polymers, characterised in that the electrocatalyst ink further comprises particulate graphite which is present at a loading of 1 to 40 weight % with respect to the weight of the electrocatalyst, and a process for the preparation of said ink is disclosed. The use of the ink in a gas diffusion electrode, particularly for use in PEM fuel cells is also disclosed.
