One pot aqueous synthesis of nanoporous Au sub(85)Pt sub(15) material with surface bound Pt islands: an efficient methanol tolerant ORR catalyst

• Published in: Nanoscale 2014-10, Vol.6 (21), p.13012-13021
• Main Authors: Anandha Ganesh, P, Jeyakumar, D
• Format: Article
• Language: English
• Subjects: Catalysts; Cathodes; Islands; Methyl alcohol; Nanostructure; Platinum; Silver; Synthesis
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c4nr04712e

For the first time, we are reporting the synthesis of Au sub(100-x)Pt sub( x) nanoporous materials in the size range of 7-10 nm through the galvanic replacement of Ag by Pt from Au sub(100-x)Ag sub(2x) spherical nano-alloys (x= 20, 15, 10 and 5) in an aqueous medium. The galvanic replacement reaction follows the 'Volmer-Weber' growth mode, resulting in the formation of surface bound platinum islands on a nanoporous gold surface. The high angle annular dark field image and low angle X-ray diffraction studies confirm the presence of nanoporous Au sub(100-x)Pt sub(x) NPs. The electrochemical studies using the Au sub(85)Pt sub(15)/C catalyst show excellent methanol tolerance behaviour and better performance towards oxygen reduction reaction (ORR) in terms of high mass activity, mass-specific activity and figure of merit (FOM) when compared to HiSPEC Pt/C commercial catalyst. Preliminary studies on a full cell using nanoporous Au sub(85)Pt sub(15)/C (loading 1.0 mg cm super(-2)) as the cathode material and Pt-Ru/C (loading: 0.5 mg cm super(-2)) as the anode material performed better (38 mW cm super(-2)) than the HiSPEC Pt/C cathode material (16 mW cm super(-2)).