Stabilizing Pt Electrocatalysts via Introducing Reducible Oxide Support as Reservoir of Electrons and Oxygen Species

The limited durability of Pt-based catalysts has largely plagued the road of proton conductive membrane fuel cell-based vehicles to the mass market for years. Herein, we overcome the degradation issue by employing intelligent catalyst design to concomitantly suppress the oxidation and dissolution of Pt via introducing reducible niobium oxide (Nb2O5) support as a reservoir for electron and oxygen species. Benefiting from the corrosion resistance of Nb2O5 and strong metal-support interactions, the Pt-Nb2O5 catalyst exhibits negligible activity decay after 70k potential cycling between 0.6 and 1.0 V and maintains compelling stability even at higher voltages. In situ X-ray absorption fine structure and theoretical calculations have revealed that the reversible dynamic change of Nb4+/Nb5+ can inhibit the strongly bonded oxygenated species formation to attenuate Pt oxidation. Meanwhile, the Pt dissolution can be gratifyingly suppressed via the spillover of oxygenated intermediates from Pt to Nb2O5, accompanied with electron flowing from Nb2O5 to Pt. This work paves a way to develop intelligent catalysts to alleviate the degradation issue of Pt-based catalysts in a wide potential window.

Automated summary

This study addresses the degradation issue of Pt-based catalysts by employing intelligent catalyst design. By introducing Nb2O5 as a reservoir, the Pt-Nb2O5 catalyst exhibits excellent stability even at high voltages, thanks to the corrosion resistance of Nb2O5 and strong metal-support interactions.