Strong Interaction between Titanium Carbonitride Embedded in Mesoporous Carbon Nanofibers and Pt Enables Durable Oxygen Reduction.

Platinum supported on high surface area carbon has been the most widely used electrocatalyst in proton exchange membrane fuel cells (PEMFC). However, conventional carbon supports are susceptible to corrosion at high potentials, leading to severe degradation of electrochemical performance. In this work, titanium carbonitride embedded in mesoporous carbon nanofibers (m-TiCN NFs) are reported as a promising alternative to address this issue. Benefiting from the interpenetrating conductive pathways inside the one-dimensional nanostructures and the embedded TiCN nanoparticles (NPs), m-TiCN NFs exhibit excellent stability at high potentials and interact strongly with Pt nanoparticles. Subsequently, m-TiCN NFs supported Pt NPs deliver remarkably enhanced oxygen reduction reaction (ORR) activity and durability, with negligible activity decay and less than 5% loss of electrochemical surface area (ECSA) after 50,000 cycles. Moreover, the fuel cell assembled by this catalyst delivers a maximum power density of 1.22 W cm-2 and merely 3% loss after 30,000 cycles of accelerated durability tests (ADT) under DOE protocols. The improved ORR activity and durability are attributed to the superior corrosion resistance of the m-TiCN NFs support and the strong interaction between Pt and m-TiCN NFs. This article is protected by copyright. All rights reserved.