Study On Preparation And Performance Of Carbon Based Catalysts For Oxygen Reduction In Anion Exchange Membrane Fuel Cells

Anion Exchange Membrane Fuel Cell?AEMFC?can significantly improve the kinetics of cathodic oxygen reduction reaction?ORR?,use non-noble metal catalysts to reduce the cost and reduce plate corrosion,thus becoming the hotspots of research in new energy field.Catalysts for ORR are the core component of AEMFC.The development of a new type of non metal catalysts for oxygen reduction has great theoretical and practical significance to promote the development of AEMFC.Melamine is used as carbon and nitrogen source to prepare graphitic carbon nitrides?g-C₃N₄?catalysts with different morphology by pyrolysis at high temperature.And the catalytic activity of the catalysts for ORR in alkaline solution was evaluated.Bulk g-C₃N₄ can be prepared by direct pyrolysis of melamine.The catalytic activity for ORR of it is demonstrated in the alkaline solution and related to the pyrolysis temperature,heating rate and holding time.Pyrolysis temperature influence the most and heating rate the least.The optimal process combination is heating up to 650 ? by 10 ? ·min-1,holding 180 min.The transfer electron number of oxygen in the bulk g-C₃N₄ prepared by the optimal process combination is 2.268.The polarization current density of-0.8 V is 0.25191 mA·cm-2Flowerlike g-C₃N₄?FC?can be prepared by high temperature pyrolysis after melamine is heated by 400 ? and treat by concentrated nitric acid.The best preparation is heating up to 600 ? by 15 ?·min-1 and holding 180 min.The transfer electron number of oxygen in this flowerlike g-C₃N₄ is 2.757.The polarization current density of-0.8 V is 0.33329 mA·cm-2 Compared with Bulk g-C₃N₄,the ORR catalytic activity of flowerlike g-C₃N₄ is increased by 32.31%.The catalytic activity of flowerlike g-C₃N₄ can be improved by doping GO?GO/FC?.The optimal doping mass ratio is 5%.The ORR catalytic activity is increased by 32.31%compared with pure flowerlike g-C₃N₄.The transfer electron number of oxygen is 2.992.No matter Bulk g-C₃N₄,flowerlike g-C₃N₄ or GO/FC all showe good stability in alkaline solution.After 500 cyclic voltammetry tests,the performance of them do not appear to decay.