Investigation of Ti-Mo mixed oxide-carbon composite supported Pt electrocatalysts: Effect of the type of carbonaceous materials

Ti0.8M0.2O2-C composites are novel supports for Pt-based fuel cell electrocatalysts with enhanced stability and CO-tolerance. In this work the effect of the type of the carbonaceous material (Vulcan XC-72, Black Pearls 2000 and graphite oxide) as well as the mixed oxide/carbon ratio was explored on the structure and the electrochemical performance of the supports and the related electrocatalysts. The composites were prepared by optimized routes tailored to the special features of the carbonaceous materials. Better CO tolerance was obtained on the catalysts containing 75 wt.% of the Ti0.8Mo0.2O2 as compared to those with high carbon content. However, the more homogeneous microstructure of the catalysts with high carbon content (75 wt.%) was identified as the key for enhanced long-term stability. Considering also the fact that the high oxide content of the catalyst increases the cell resistance, the Black Pearls-based Pt electrocatalysts with Ti0.8Mo0.2O2/C = 25/75 ratio seem to be the most promising.