One-pot synthesis of Au@Pt star-like nanocrystals and their enhanced electrocatalytic performance for formic acid and ethanol oxidation
The current bottleneck facing further developments in fuel cells is the lack of durable electrocatalysts with satisfactory activity. In this study, a simple and fast one-pot wet-chemical method is proposed to synthesize novel Au@Pt star-like bimetallic nanocrystals (Au@Pt SLNCs) with a low Pt/Au ratio of 1:4, which show great electrocatalytic properties and outstanding stability toward the electro-oxidation reactions commonly found in fuel cells. The star-like Au core (90 ± 20 nm) is partially coated with 5 nm Pt nanocluster shells, a morphology which creates a large amount of boundaries and edges, thus tuning the surface electronic structure as demonstrated by X-ray photoelectron spectroscopy and CO-stripping measurements. This promotes excellent electrocatalytic performance towards the formic acid oxidation reaction in acidic media and the ethanol oxidation reaction in alkaline media, compared to commercial Pt or Au@Pt triangular nanoprisms, in which the Au core is fully coated by a Pt shell. Au@Pt SLNCs have the highest current density within the dehydrogenation potential range, needing the least potential to achieve a certain current density as well as the highest long-term stability. Because of the small amount of Pt usage, very fast synthesis, excellent electrocatalytic activity and durability, the proposed Au@Pt SLNCs have a promising practical application in fuel cells.
KeywordsAu@Pt core–shell nanocrystals electrocatalyst formic acid ethanol oxidation
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This work was financially supported by the National Natural Science Foundation of China (No. 21273001) and the National Basic Research Program of China (No. 2014CB931802).
- Ren, F. F.; Wang, H. W.; Zhai, C. Y.; Zhu, M. S.; Yue, R. R.; Du, Y. K.; Yang, P.; Xu, J. K.; Lu, W. S. Clean method for the synthesis of reduced graphene oxide-supported PtPd alloys with high electrocatalytic activity for ethanol oxidation in alkaline medium. ACS Appl. Mater. Interfaces 2014, 6, 3607–3614.CrossRefGoogle Scholar
- Wanjala, B. N.; Luo, J.; Loukrakpam, R.; Fang, B.; Mott, D.; Njoki, P. N.; Engelhard, M.; Naslund, H. R.; Wu, J. K.; Wang, L. C. et al. Nanoscale alloying, phase-segregation, and core–shell evolution of gold-platinum nanoparticles and their electrocatalytic effect on oxygen reduction reaction. Chem. Mater. 2010, 22, 4282–4294.CrossRefGoogle Scholar
- Kristian, N.; Yan, Y. S.; Wang, X. Highly efficient submonolayer Pt-decorated Au nano-catalysts for formic acid oxidation. Chem. Commun. 2008, 353–355.Google Scholar
- Zhang, B. W.; Zhang, Z. C.; Liao, H. G.; Gong, Y.; Gu, L.; Qu, X. M.; You, L. X.; Liu, S.; Huang, L.; Tian, X. C. et al. Tuning Pt-skin to Ni-rich surface of Pt3Ni catalysts supported on porous carbon for enhanced oxygen reduction reaction and formic electro-oxidation. Nano Energy 2016, 19, 198–209.CrossRefGoogle Scholar