Cu-incorporated PtBi intermetallic nanofiber bundles enhance alcohol oxidation electrocatalysis with high CO tolerance

Atomically ordered intermetallic nanomaterials represent one class of the most attractive catalysts for direct alcohol fuel cells, whereas they remain arduous owing to both the complexity of conventional synthetic approaches and their susceptibility to intermediates (especially CO). Herein, a facile one-step surfactant-free strategy is reported for producing Cu-incorporated PtBi intermetallic nanofiber bundles (Cu-PtBi NFBs) served as robust electrocatalysts towards bifunctional methanol and ethanol oxidation reactions (MOR and EOR). The resultant Cu-PtBi NFBs not only achieve remarkable CO tolerance, and superior mass and specific activities (6.79 A mg(Pt)(-1) and 11.26 mA cm(-2)) with a maximum onset potential shift (77 mV) relative to commercial Pt/C for the MOR, but also show 4.3-fold improved EOR mass activity (4.00 A mg(Pt)(-1)) compared to commercial Pt/C. X-ray absorption fine structure analysis and density functional theory simulation corroborate that the ordered PtBi-based hexagonal close-packed structure, as well as the Cu-induced bifunctional effect, is key to substantially weakening the bonding strength between CO* and Pt sites and strengthening the anchoring of OH* on adjacent Cu sites, thereby optimizing the CO-poisoning pathway. This work provides an effective design strategy for Pt-based intermetallic nano-electrocatalysts as high-efficiency anodic materials in fuel cell applications.

Automated summary

This study reports a facile surfactant-free strategy for producing Cu-incorporated PtBi intermetallic nanofiber bundles, which exhibit excellent electrocatalytic performance towards methanol and ethanol oxidation reactions. The Cu-PtBi NFBs show remarkable CO tolerance, superior mass and specific activities, as well as improved efficiency compared to commercial Pt/C, making them promising anodic materials for fuel cell applications. X-ray absorption fine structure analysis and density functional theory simulation confirm the key role of ordered PtBi-based structure and Cu-induced bifunctional effect in optimizing the CO-poisoning pathway.