Research On The Synthesis And Oxygen Reduction Reaction Performance Of The Heteroatomic Doping Carbon/transition Metal Composite Material

Oxygen reduction reaction?ORR?is very important for both the fuel cell and the metal air batteries.Researches on high catalytic active catalystfor ORR is of great significance.At present,platinum catalyst is considered to be the most efficient.However,due to its low reserves,large-scale applications of platinum have been restricted greatly.Recently,transition metals and their compounds as a new type of ORR catalyst have shown unique catalytic properties.However there still exit many problems with transition metals and their compounds catalyst,such as the relatively complex preparation methods,the unclear catalyst active site and the poor catalyst activity under acid environment.In this article,series of non platinum transition metal/carbon catalysts were synthesized.Composition,structure,catalyst activity and the relations between them were researched in detail.In the second chapter,cobalt embedded nitrogen doped carbon nanotubes were synthesized through solvent thermal process.The results confirm that the as-prepared products show more uniform morphology,larger pore structure and pore volume,rich in pyridine nitrogen content and special Co-N_x surface structure compared to the products without the solvent thermal process.All these properties make Co-NC has perfect electrochemical catalytic activity and stability.In the third chapter,three transition metal?Fe,Co,Ni?sulfides were synthesized through orthogonal design method.Results show that iron based transition metal sulfides compared with cobalt sulfides and nickel-based catalysts have higher initial reduction potential.And nickel base sulfide can show excellent electrical conductivity,in the existing samples shows the highest limiting diffusion current.Different transition metal sulfides exhibit different catalytic properties,which will guide for the binary composite sulfide for further research.In the fourth chapter,using MMT as nanoreactor to limit the growth of the MOF material,ultra-thin N,S doped carbon nanotubes pieces composited with Co and Co₉S₈ catalysts were synthesized.The catalysis shows excellent electric catalytic activity and the reaction is nearly four electronic process.