A highly stable catalyst for PEM fuel cell based on durable titanium diboride support and polymer stabilization

Titanium diboride (TiB2) is an electrically conducting ceramic with good conductivity, excellent thermal stability and corrosion resistance in acid medium. Here we report for the first time its application as a new catalyst support in proton exchange membrane (PEM) fuel cells. This novel catalyst (Pt/TiB2) was formed by a colloid route, in which the highly dispersed Pt nanoparticles were stabilized by Nafion functional polymers. This significantly facilitates the dispersion of Pt nanoparticles on TiB2. The electrochemical stability of TiB2 was investigated and showed almost no changes in redox region after oxidation during 48 h at 1.20 V. Further, it was found that the electrochemical stability of Pt/TiB2 catalyst is about four times higher than that of the commercial Pt/C under electrochemical oxidation cycles in the potential range of 0.6–1.2 V. The excellent stability of Pt/TiB2 could be attributed to the stability of TiB2 support as well as the introduction of Nafion as stabilizer, which enhance both the metal–support interaction and the steric hindrance effect of the surface of Pt nanoparticles.