Construction of Porous PtCo Alloy Nanotubes via an Epitaxial Growth Method for Efficient and Stable Electrochemical Oxygen Reduction Reaction.

Abstract

Developing efficient and robust oxygen reduction reaction electrocatalysts is important for practical proton exchange membrane fuel cell (PEMFC) applications. However, substantial challenges persist in constructing interfacial architectures to improve the mass activity and durability. Herein, a seeded epitaxial growth method is developed to precisely construct one-dimensional core-shell nanostructures with Pt growth layers. The derived 1D porous Pt₃Co nanostructured material undergoes surface evolution after electrochemical cycling, exhibiting optimized oxygen reduction reaction catalytic activity and excellent stability. The surface evolution process induced by electrochemical cycling generates compressive strain on the Pt surface, which optimizes the adsorption of oxygen-containing intermediates and, thereby, enhances the oxygen reduction reaction (ORR) activity. In addition, the resulting strained Pt-rich surface structure elevates the formation energy of the Pt vacancy, thereby improving the corresponding electrochemical durability. This work provides a new revenue for the precise construction of multidimensional Pt-based nanostructures and optimization of interface structures.