Composition, structure and stability of PtCu/C electrocatalysts with non-uniform distribution of metals in nanoparticles

Carbon supported Pt–Cu electrocatalystElectrocatalyst with increased platinumPlatinum content in the surface layer of nanoparticles was synthesized by a sequential chemical reduction of Cu (II) and Pt (IV) compounds from their solutions. A subsequent thermo-treatmentThermo-treatment and the combination ofThermo-treatment thermo- and corrosion treatmentCorrosion treatment of the catalyst resulted in a slight increase in an average crystallite size, but had not an essential negative impact on the electrochemically active surface area (ESA) value. During stabilityStability tests (1000 voltammetric cycles), the values of ESA for pristine and post-treatedPost-treated Pt–Cu/C catalystsCatalysts decreased by 15–20% from 61–65 to 56 m2g−1 (Pt). In similar tests of commercial Pt/C catalyst TEC10v30e an ESA value decreased by 56% from 80 to 36 m2g−1 (Pt). High stabilityStability of the prepared Pt–Cu/C catalystsCatalysts in combination with high ESA values and oxygen reduction reactionoxygen reduction reaction activity may be since, despite the comparatively large size of nanoparticles, the majority of them have a core-shellCore-shell or hollow structure. The obtained result demonstrates the prospect of using bimetallic catalyst systems with an uneven surface distribution of metals in nanoparticles as electrocatalystElectrocatalyst in low temperature fuel cells and shows a way of combining high activity and durability of the electrocatalystElectrocatalyst .