Pt Particles Functionalized on the Molecular Level as New Nanocomposite Materials for Electrocatalysis

International audienceA nanocomposite material consisting of platinum nanoparticles surrounded by an ionic conducting polymer dispersed on carbon Vulcan XC72 was synthesized. The aim of this nanocomposite material is to translate the triple-phase boundary to a molecular level in electrochemical systems involving a polymer electrolyte. The ionic conducting polymer is a poly(styrenesulfonic acid) (PSSA, or PSSNa in its sodium form) synthesized by atom-transfer radical polymerization. The polymer has a terminal thiol group to ensure bonding with platinum nanoparticles. The nanocomposite material (Pt-PSSA/C) exhibited thermal stability up to 160 degrees C and electrochemical stability up to 1 V versus RI-LE. Compared to a Pt/C catalyst, the nanocomposite catalyst has a lower active surface area but comparable catalytic activity for the oxygen reduction reaction. Furthermore, this nanocomposite material exhibits similar behavior in a fuel cell active layer without Nafion as a classical Pt/C catalyst with Nafion included in the active layer