Method for preparing proton-conducting particles suitable for catalysing oxygen reduction or hydrogen oxidation by grafting specific proton-conducting polymers to the surface of same

Method for preparing particles comprising a material able to catalyse oxygen reduction or hydrogen oxidation, said particles being grafted with grafts composed of at least one polymer comprising at least styrene repeating unit carrying at least one proton-conducting group, said method comprising:

• a) a step to prepare at least one styrene polymer via ATRP polymerisation of a styrene monomer with an ATRP initiator meeting following formula (I):
• where:
• the R1 groups are each independently an organic spacer group;
• the Z groups are each independently a single bond or an organic spacer group;
• the R2 groups are each independently a halogen atom;
• the resulting polymer meeting following formula (II):
• where Y corresponds to the styrene repeating unit carrying at least one proton-conducting group and n1 to the number of repeats of the repeating unit between round brackets, R1, R2 and Z being such as defined above;
• b) a step to place the particles comprising a material able to catalyse oxygen reduction or hydrogen oxidation in contact with the polymer obtained at a), after which particles are obtained grafted with grafts of following formula (III):
• the brace indicating the point at which the grafts are covalently bonded to the particles, and R1, R2, Z, Y and n1 being such as defined above.