|
چکیده
|
The sources of electric power are mostly derived from fossil fuels, which has a negative impact on the environment, and also population growth and the importance of tecchnology in socity have both contributed to the upsurge in the demand for energy. Recently, research in the field of direct alcohol fuel cells due to advantages such as low cost, portability, high-energy density, low operating temperature, and relatively significant efficiency, has attracted much attention from researchers[1]. 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 of suitable 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 for MOR have been designed, synthesized, and extensively studied [2]. However, supported Pt-based catalysts are the most active electrocatalysts for MOR in practical DMFCs. The support can promote the formation of highly distributed catalyst nanoparticles with small size and narrow size distribution [3]. Recently, graphene (G) is regarded as a novel and promising support for the preparation of noble metal/G hybrids. The hybride of noble metal and graphene show better activity and stability for alcohol oxidation due to the increasing electrochemical active surface area (ESA) and effectively accelerating electron transfer during the alcohol oxidation reaction. Based on this view, we choose graphene as support to prepare PtCu/G hybrids in our work [4]. In this work, the sulfur-modified graphene supported Pt–Cu alloy nanoparticles have been synthesized and used for MOR in acidic solutions. The catalysts were prepared by impregnation of the catalyst precursors on the graphene support and then alloying at high temperature under an atmosphere of H2/N2. The improved electrochemical response and facile synthesis make the present method promising for the preparation of graphene-supported well-dispersed pure metal and alloy nanoparticles of small size and narrow size distribution.
|