Co_(1-x)S-Graphene Hybrid: A High-Performance Metal Chalcogenide Electrocatalyst for Oxygen Reduction

摘要

Owing to their high energy-conversion efficiency, low or even zero emission, and high energy and power density, fuel cells such as proton-exchange membrane fuel cells (PEMFC) and direct methanol fuel cells (DMFC) have drawn tremendous attention as potential clean and efficient power sources for both electric vehicles and portable electronics.A major limiting factor of energy-conversion efficiency for present fuel cells is the sluggish kinetics of the oxygen reduction reaction (ORR) at the cathode.Platinum and its alloys have been so far the most active ORR catalysts. However, the prohibitive cost, scarcity, and declining activity of Pt-based catalysts have hindered widespread application and commercialization of fuel cells. Consequently, alternative electro-catalysts based on nonprecious metals have been actively pursued.