A comparative study on catalytic activity and stability of TiO2, TiN, and TiC supported Pt electrocatalysts for oxygen reduction reaction in proton exchange membrane fuel cells environment

Abstract

The serious corrosion of carbon support in the Pt-based catalysts, resulting in their instability, is one of the most important technical issues hampering the wide application of proton exchange membrane fuel cells (PEMFCs). In order to address this issue, TiO2, TiN, and TiC supported Pt nanoparticles (NPs) catalysts were synthesized using a simple polyol process and their oxygen reduction reaction (ORR) activity and durability have been investigated in acidic media of PEMFCs using rotating disk electrode (RDE) technique and compared with the commercial carbon supported Pt catalyst. The average Pt NPs sizes are 2.3, 2.3, and 2.6nm for the Pt/TiO2, Pt/TiN, and Pt/TiC catalysts, respectively. Among these three synthesized catalysts, the Pt/TiC catalyst has the highest stability and best catalytic performance with higher ORR current, electrochemical surface area (ECSA) and mass-specific activity. The ORR performance of the synthesized Pt/TiC catalyst is found to be promising with higher area-specific activity (Is) of 252.6 μA cmPt−2 and almost identical mass-specific activity (Im) of 0.16 A mgPt−1 than that of the Pt/C with Is of 235.5 μA cmPt−2 and Im of 0.17 A mgPt−1 at E=0.9V in 0.1M HClO4 solution. Additionally, the Pt/TiC shows the outstanding stability with no reduction in ORR performance and 10.1% increase in ECSA after accelerated stress test (AST).