Synthesis of Pt-Cu alloy nanoparticles on sulfur-modified graphene aselectrocatalysts for methanol oxidation reaction

The sources of electric power are mostly derived from fossil fuels, which has a negative impacton the environment, and also population growth and the importance of tecchnology in socity haveboth contributed to the upsurge in the demand for energy. Recently, research in the field of directalcohol fuel cells due to advantages such as low cost, portability, high-energy density, lowoperating temperature, and relatively significant efficiency, has attracted much attention fromresearchers[۱]. Direct methanol fuel cells (DMFCs), compared with hydrogen-powered fuel cells,are widely used as mobile and portable power sources due to their portability and high efficiency.Although the current research on DMFCs has made great progress, due to the unavailability ofsuitable catalysts for methanol oxidation reaction (MOR), it still cannot be widely commercialzed.Up to now, a number of catalysts based on supported noble metal including Pt, Ru, and Pd forMOR have been designed, synthesized, and extensively studied [۲]. However, supported Pt-basedcatalysts are the most active electrocatalysts for MOR in practical DMFCs. The support canpromote the formation of highly distributed catalyst nanoparticles with small size and narrow sizedistribution [۳]. Recently, graphene (G) is regarded as a novel and promising support for thepreparation of noble metal/G hybrids. The hybride of noble metal and graphene show betteractivity and stability for alcohol oxidation due to the increasing electrochemical active surface area(ESA) and effectively accelerating electron transfer during the alcohol oxidation reaction. Basedon this view, we choose graphene as support to prepare PtCu/G hybrids in our work [۴]. In thiswork, the sulfur-modified graphene supported Pt–Cu alloy nanoparticles have been synthesizedand used for MOR in acidic solutions. The catalysts were prepared by impregnation of the catalystprecursors on the graphene support and then alloying at high temperature under an atmosphere ofH۲/N۲. The improved electrochemical response and facile synthesis make the present methodpromising for the preparation of graphene-supported well-dispersed pure metal and alloynanoparticles of small size and narrow size distribution.

کلیدواژه ها:

Methanol Oxidation Reaction ، Geraphene ، PtCu ، alloy