Self-assembly of Pd Nanoparticles on Anatase Titanium Dioxide and Their Application in Formic Acid Fuel Cells

Based on electrostatic self-assembly technology, Pd electrocatalyst with high efficiency and excellent CO-tolerance, which is supported on TiO 2 surface modified by amino-rich, cationic poly (diallyldimethylammonium chloride) (PDDA), was prepared. Through electrostatic interaction, Pd precursors were uniformly distributed on TiO 2 (P) and then in situ reduced into Pd nanoparticles (NPs). in such process, PDDA produced a large number of amine to facilitate the uniform distribution of Pd NPs on the surface of TiO 2 . After that，Pd/TiO 2 (P) was mixed with carbon black as anodic catalysts for formic acid oxidation reaction. Transmission electron microscope images and X-ray diffraction patterns revealed that Pd NPs with an average size of ∼3 nm were uniformly dispersed on TiO 2 . Moreover, with the application of cyclovoltammetry and chronoamperometry, we demonstrated the significant enhancement in the electrocatalytic activity and the tolerance toward CO poisoning when compared with Pd/TiO 2 -C for direct formic acid fuel cells.