Nb-TiO2 nanotubes as catalyst supports with high activity and durability for oxygen reduction

Abstract

Platinum is the most effective catalyst for oxygen reduction in proton-exchange membrane fuel cells (PEMFCs). Nevertheless, significant problems must be addressed for the effective use of Pt, such as the extremely low Pt utilization in the electrocatalysts and low durability due to corrosion of the support. Here, we present a promising approach for addressing these challenges by the facile synthesis of Nb-TiO2 nanotubes as efficient support for Pt-based electrocatalysts. The Pt/Nb-TiO2 nanotubes led to a marked enhancement of the oxygen reduction reaction kinetics, attributed to the increased electronic conductivity and strong metal-support interaction of the Nb-TiO2 support. Moreover, compared to the state-of-the-art conventional Pt/carbon catalyst, the Pt/Nb-TiO2 nanotubes show high durability because of their structural stability and retention of the high surface area during post-processing. The mass activity of the conventional Pt/C decreased by 37% after the ADT (126.9 and 80.1 A g−1 Pt before and after ADT, respectively), whereas that of Pt/Nb-TiO2 was merely reduced by 22% (285.1 and 222.6 A g−1 Pt before and after ADT, respectively). © 2020 Elsevier B.V.