Method for producing proton-conducting platinum particles with a large active surface area and surface-grafted with specific, proton-conducting polymers

Method for preparing platinum particles bonded to a carbon material, said particles being grafted with grafts consisting of at least one polymer comprising at least one styrene repeating unit having at least one proton-conducting group, said method comprising:

• a) a step of preparing said platinum particles bonded to a carbon material comprising an operation of heating under microwaves of a mixture comprising a platinum salt, said carbon material and at least one polyol compound, subject to which said particles are obtained;
• b) a step of preparing at least one ethylene polymer by ATRP polymerisation of an ethylene monomer with an ATRP initiator having the following formula (I):
• wherein:
• the R1 groups represent, independently of one another, an organic spacer group;
• the Z groups represent, independently of one another, a single bond or an organic spacer group;
• the R2 groups represent, independently of one another, a halogen atom;
• the resulting polymer having the following formula (II):
• wherein Y corresponds to the styrene repeating unit having at least one proton-conducting group and n1 to the repetition number of the repeating unit taken in parentheses, the R1, R2 and Z being such as defined hereinabove;
• c) a step of contacting particles obtained in a) with the polymer obtained in b), subject to which particles are obtained grafted with grafts having the following formula (III):
• the brace indicating the location where the grafts are bonded, covalently, to the particles and the R1, R2, Z, Y and n1 being such as defined hereinabove.