摘要
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.
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.
