Laser-optimized Pt-Y alloy nanoparticles embedded in Pt-Y oxide matrix for high stability and ORR electrocatalytic activity

Abstract

The development of active yet stable catalysts for oxygen reduction reaction (ORR) is still a major issue for the extensive permeation of fuel cells into everyday technology. While nanostructured Pt catalysts are to date the best available systems in terms of activity, the same is not true for stability, particularly under operating conditions. In this work, PtXY alloy nanoparticles are proposed as active and durable electrocatalysts for ORR. PtXY nanoalloys are synthesized and further optimized by laser ablation in liquid followed by laser fragmentation in liquid. The novel integrated laser-assisted methodology succeeded in producing PtxY nanoparticles with the ideal size (< 10 nm) of commercial Pt catalysts, yet resulting remarkably more active with E1/2 = 0.943 V vs. RHE, specific activity = 1095 μA cm−2 and mass activity > 1000 A g−1. At the same time, the nanoalloys are embedded in a fine Pt oxide matrix, which allows a greater stability of the catalyst than the commercial Pt reference, as directly verified on a gas diffusion electrode.