Fabrication Of Phthalocyanine Covalently Functionalized Graphene Composites And Their Application For The Cathodic Catalyst In Fuel Cell

Energy and environmental issues become increasingly prominent in modern society, human beings should develop a kind of new clean energy rise to the occasion. DMFC is a new type of energy conversion device, which possess high energy conversion efficiency and non-pollution, these performance has aroused much concern in recent years.Platinum (Pt) is regarded as the best ORR catalyst for DMFC because it provides the lowest overpotential and the highest current response towards a direct4-electron reduction of oxygen to water. However, Pt suffers from the disadvantages of high price and extreme scarcity, which prevent the wide application of commercial fuel cells in our daily life. Another fatal factor for the whole performance of Pt is poor tolerance to the crossover effect. To overcome these problems, it is urgent to find highly efficient ORR electrocatalysts which are low cost and durable for replacing Pt and Pt-based catalysts.In this paper, we synthesized a series of phthalocyanine-graphene composite catalyst for ORR by reduction of the product obtained through an amidation reaction between GO/CFGO and tetra-aminophthalocyanine. The composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy (RS) and X-ray photoelectron spectroscopy (XPS), respectively. Cyclic voltammetry (CV), rotating disk electrode (RDE) and rotating ring disk electrode (RRDE) measurements were performed to assess the electrocatalytic activity and explore catalytic mechanism of the fabricated catalyst towards the ORR. The peak potential of the ORR on the Fe2+Pc-CFGr catalyst was found to be about-0.12V vs. SCE in0.1M NaOH solution. RDE and RRDE measurements revealed that the ORR mechanism was nearly via a direct four-electron pathway to water. The current still remained83.5%of its initial after chronoamperometric test for10000s. The peak potential and peak current changed slightly when3M methanol was introduced. So this composite catalyst for ORR exhibited high activity, good stability and methanol-tolerance, which could be used as a promising Pt-free catalyst for ORR in alkaline DMFC.