Electroreduction of oxygen on Pd catalysts supported on Ti-modified carbon

Carbon supports modified with well dispersed anatase TiO ₂ (C-Ti-X; X (0.25, 0.5, 0.75, and 1.0) represents mass ratio of Ti precursor to carbon) were synthesized with various Ti loadings and used to support Pd catalysts for oxygen reduction. The anatase nanoparticles increased in size with increasing Ti loading. Pd dispersion improved with increasing Ti loading up to the C-Ti-0.75, which resulted in the best catalytic activity. Although the Pd dispersion was lowest on the C-Ti-1.0, it showed better catalytic performance than the catalysts supported on C-Ti-0.25 and C-Ti-0.5. At 0.8 V (vs. RHE), the best catalytic activity achieved was respectively 2.7 and 2.7 times the mass and specific activities of Pd supported on un-modified carbon. The interaction between Pd and highly dispersed TiO ₂ is believed to improve the catalytic activity of Pd supported on TiO ₂-modified carbons.