Hollow porous PtFe nanospheres prepared by a cyanogel-derived strategy for formic acid oxidation

Exploring efficient electrocatalysts for the formic acid oxidation reaction (FAOR) through a dehydrogenation pathway is important for the widespread use of direct formic acid fuel cells (DFAFCs). The direct pathway, reactivity and stability of the FAOR can be enhanced by modulating the surface atomic composition and state, as well as the morphological structure of the Pt-based catalyst. In this study, we present a straightforward and mild cyanogel-derived method to prepare PtFe alloy nanospheres with a hollow porous structure by using the K₂PtCl₄/K₄Fe(CN)₆ cyanogel as precursors. The fabricated hollow porous PtFe nanospheres exhibit an enhanced dehydrogenation pathway and improved electrocatalytic activity and stability in comparison with the commercial Pt black catalyst, owing to the hollow porous structure with abundant active sites and synergistic effects between the alloy metals, inhibiting the formation of the toxic species CO_ads. The cyanogel-derived synthetic strategy presented here has the potential to be applied for fabricating other multicomponent nanoalloys with satisfactory morphology and excellent electrochemical performance.