Preparation of highly dispersed Pt on TiO₂-modified carbon for the application to oxygen reduction reaction

The carbon support (C) is modified by its functionalized surface with Ti species and used as a support of Pt catalyst for oxygen reduction reaction (ORR). Anatase TiO₂ nanoparticles with the size of 3-5 nm are uniformly dispersed on the modified carbon support (C-Ti). It is shown that the C-Ti is well dispersed in the solution of Pt precursor due to the hydrophilic TiO2 nanoparticles. This causes a uniform distribution of Pt nanoparticles on C-Ti support. The average particle sizes are 2.9, 2.6, and 3.1 nm, respectively, for Pt/C, Pt/C-Ti, and Pt-commercial. The ORR performance is evaluated in terms of both massactivity and specific activity. It is found that the Pt/C-Ti revealed the highest performance. The enhancement factors of ORR performance on the Pt/C-Ti at the potentials of 0.75, 0.8, and 0.85 V was more than two for both mass activity and specific activity compared to those on the Pt/C. The large surface area of Pt with a favorable electronic structure would be responsible for a superior performance of the Pt/C-Ti in ORR.