Brush-Like Hollow PtTe2 Nanotube for Enhanced Formic Acid Electrooxidation Catalysis

Abstract

The serious CO poisoning for traditional Pt-based catalysts often results in a large deterioration in activity and stability of formic acid oxidation reaction (FAOR), which severely restricts the development of direct formic acid fuel cells. It is of great significance and challenging to enhance the CO tolerance for an advanced Pt-based catalyst. Whereupon, in this work, successful synthesis of a brush-like hierarchical structure composed by ordered ultrathin PtTe₂ intermetallic compounds is achieved. Benefiting from the electron transfer from Pt to Te, the relatively poor electron density of Pt can assist the down shift of the d-band center of PtTe₂, which greatly weakens the adsorption affinity toward CO and enhances the antipoisoning ability. Besides, in situ infrared spectroscopy and density functional theory simulation further confirm the special electron structure can promote the dehydrogenation pathway during the whole FAOR proceeding. Specifically, the mass activity of PtTe₂ is up to 4.72 A mg_pt^–1, which is about 9.25-fold higher than that of the commercial Pt/C. In addition, PtTe₂ still has higher catalytic activity than commercial Pt/C even after 3 h. This work inspires targeted enhancement of the antipoisoning properties of Pt-based catalysts through the design of atomic level ordered structure and ultrathin two-dimensional morphology and is beneficial to the considerable progress of fuel cell catalysis.