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

Abstract

Nanostructural clusters (NCs) of dendritic Pt on Ti0.7Mo0.3O2 nanosupports (Ptd/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. 20wt% dendritic Pt/Ti0.7Mo0.3O2-NCs and support-free Pt nanodendrite catalysts were prepared and compared against commercial 20wt% 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.