Nanotube-shaped PtFe intermetallics: controlled synthesis, crystal structure, and improved electrocatalytic activities

Abstract

Well-shaped intermetallic compounds with unique electronic structures and characteristic long range atomic orders have gained tremendous interest due to their attractive electrocatalytic performances and promising long-term durabilities. In this study, we report a facile strategy for the efficient synthesis of ordered PtFe intermetallics in nanotube shapes using cost-effective premade elongated β-FeOOH as a microstructure template followed by surface self-assembly with an ultra-thin layer of platinum shell and controlled heat treatments under mild experimental conditions. Compared to the commercial Pt black catalyst, the proposed ordered PtFe intermetallic nanotubes (NTs) exhibit an enhancement in mass activity (536.67 A g⁻¹) by a factor of 2.0 and specific activity (61.64 A m⁻²) by 5.8 for the methanol oxidation reaction (MOR). These results pave the way for the fabrication of well-shaped ordered intermetallic catalysts towards practical applications in fuel cells.