Evaluation of the durability of ZrC as support material for Pt electrocatalysts in PEMFCs: Experimental and computational studies

Abstract

Zirconium carbide (ZrC) is evaluated as support material for corrosion resistance to replace carbon in Pt electrocatalyst for the first time. The commercial ZrC (1 m2g-1) is activated using solid sodium carbonate producing high surface area activated ZrC (a-ZrC, 134 m2g-1). Both ZrC and a-ZrC exhibit good corrosion resistance properties during carbon corrosion tests. As supports in Pt/ZrC and Pt/a-ZrC electrocatalysts, the ECSA losses are below 40% after standard accelerated stress test protocols satisfying the standard set targets of DoE. The Pt/ZrC does not show significant shift in the onset potential in the linear sweep voltammetry after start-up and shut-down protocol tests. The shift in E1/2 potentials for Pt/ZrC and Pt/a-ZrC catalysts, respectively, are 13 mV and 24 mV, which are less compared to 30 mV for Pt/C. The computational analysis shows strong-metal-support-interaction between ZrC and Pt which is responsible for catalyst durability because of higher dissolution potential.