Synthesis of Ti0.7Mo0.3O2 supported-Pt nanodendrites and their catalytic activity and stability for oxygen reduction reaction

Nanostructural clusters (NCs) of dendritic Pt on Ti0.7Mo0.3O2 nanosupports (Pt-d/Ti0.7Mo0.3O2-NCs) were synthesized by a simple aqueous-phase route. PtCl62- -ions were reduced and formed nuclei under the effect of L-ascorbic acid and cetyltrimethylammonium bromide (CTAB). There followed controlled deposition and growth of Pt nanoparticles with high-index facets of Pt. In the synthesis, the clustering of the Pt particles could be driven by their high surface energy due to a large surface area-to-volume ratio. 20 wt% dendritic Pt/Ti0.7Mo0.3O2-NCs and support-free Pt nanodendrite catalysts were prepared and compared against commercial 20 wt% Pt/C (E-TEK) for oxygen reduction reaction (ORR). TEM, XRD, X-ray absorption near edge structure (XANES), and electrochemical techniques were applied to characterize these catalysts. Effects of high index facets on dendritic Pt surface, electron transfer originating from strong metal-support interactions (SMSI) and corrosion-resistant Ti0.7Mo0.3O2 nanosupport contribute to the enhanced catalytic activity and stability of Pt/Ti0.7Mo0.3O2-NCs toward the ORR. The concept of the Ptd/Ti0.7Mo0.3O2-NCs combining advantages of SMSI and Pt nanodendrites provides a new approach to design novel nanocatalysts for various reaction systems. (c) 2014 Elsevier B.V. All rights reserved.