Simultaneous tunable structure and composition of PtAg alloyed nanocrystals as superior catalysts. Issue 32 (28th July 2016)

• Record Type: Journal Article
• Authors: Fang, Caihong; Zhao, Jun; Zhao, Guili; Kuai, Long; Geng, Baoyou
• Is Part Of: Nanoscale. Volume 8:Issue 32(2016)
• Page Start: 14971
• Page End: 14978
• Publication Date: 2016-07-28
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c6nr02643e
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : Porous PtAg alloyed nanocrystals with tunable structure and composition were prepared. The alloys can be tuned from multipetals to multioctahedra with composition varying from Pt76 Ag24 to Pt66 Ag34 . The PtAg exhibit superior catalytic performances toward the reduction of 4-nitrophenol and methanol oxidation reaction. Abstract : PtAg alloyed nanostructural catalysts were firstly prepared by co-reduction of AgNO3 and H2 PtCl6 precursors in growth solution using a seed-mediated method. By simply changing the molar ratio of the metal precursors, the morphologies of the porous alloyed nanocrystals can be tuned from multipetals to multioctahedra. Simultaneously, the alloy composition can be varied from Pt76 Ag24 to Pt66 Ag34 . The catalytic properties of the prepared PtAg alloyed nanocrystals with a tunable structure and composition were tentatively examined by choosing the reduction of 4-nitrophenol with NaBH4 . The reaction rate normalized to the concentration of catalysts was calculated to be 318.9 s −1 mol −1 L and 277.4 s −1 mol −1 L for Pt70 Ag30 and Pt66 Ag34 porous catalysts, which is much higher than the pure Pt catalysts. Moreover, PtAg nanostructures can also serve as efficient electrocatalysts toward the methanol oxidation reaction, especially for Pt70 Ag30 and Pt66 Ag34 porous nanocrystals. The electrocatalytic activity and the durability were both highly enhanced compared to the commercial Pt/C catalyst. In addition, we also investigated the enhancement mechanism.