Amorphization-Facilitated Synthesis of Pt2Bi2/Pt Heterojunction Nanorods for Highly Efficient Methanol Electrooxidation.

To address the low atomic efficiency and CO poisoning susceptibility of Pt-based nanomaterials in methanol oxidation reactions (MOR), we develop a facile template-directed approach to heterogeneous Pt2Bi2/Pt nanorods (Pt2Bi2/Pt NRs) utilizing Bi2S3 NRs as a template. The formation of Pt2Bi2/Pt NRs is assisted by surface amorphization of Bi2S3 NRs, facilitating the subsequent Pt deposition and alloying process. Notably, Pt2Bi2/Pt NRs display a mass activity of 5.13 A mgPt-1 for MOR, which is over five times higher than that of commercial Pt/C (0.98 A mgPt-1), as well as greatly enhanced stability. In situ infrared spectroscopy and density functional theory calculations indicate that the electronic structure of Pt2Bi2/Pt NRs could modify the adsorption/desorption of reaction intermediates and facilitate MOR via a CO-free pathway, circumventing the typical CO poisoning observed in conventional Pt-based electrocatalysts. This study provides a synthetic route for rationally designing heterostructured electrocatalysts with superior performance.