Multiscale Regulation of Ordered PtCu Intermetallic\nElectrocatalyst for Highly Durable Oxygen Reduction Reaction

Abstract

Transforming\nthe Pt–M alloy into an ordered intermetallic\nis an effective strategy to improve the electrocatalytic activity\nand stability toward the oxygen reduction reaction (ORR). However,\nthe synthesis of nanosized intermetallics remains challenging. Herein,\nwe report an efficient ORR electrocatalyst, consisting of a monodisperse\nnanosized PtCu intermetallic on hollow mesoporous carbon spheres (HMCS).\nAs predicted by theoretical calculations, PtCu intermetallics exhibit\nbeneficial electronic structure, with a low theoretical overpotential\nof 0.33 V and enhanced Cu stability. Resulting from the multiscale\nmodulation of catalyst structure, the O-PtCu/HMCS catalyst delivers\na high mass activity of 2.73 A cm^–2_Pt at 0.9 V and remarkable stability. Identical location transmission\nelectron microscopy (IL-TEM) investigations demonstrate that the rate\nof carbon corrosion is alleviated on HMCS, which contributes to the\nlong-term durability. This work provides a promising design strategy\nfor an ORR electrocatalyst, and the IL-TEM investigations offer new\nperspectives for the performance enhancement mechanism.