Studies On The Preparation,Intramolecular Structure Regulation And Electrocatalytic Performance Of Porous Carbon Materials

The catalytic activity and stability of oxygen reduction reactions（ORR）under acidic and alkaline conditions have always been the focus of research and the key to the next generation of energy storage and conversion technologies.How to prepare ORR catalysts with high activity and stability is the focus of current research.In this paper,a series of nitrogen-doped porous carbon nanomaterials were prepared and their ORR catalytic activity and stability under acidic and alkaline conditions were investigated.The first chapter is the introduction,which mainly summarizes the research progress of the existing materials in ORR,elaborates the advantages and disadvantages of various materials synthesis methods and properties,and proposes the research ideas of this paper.The second chapter briefly introduces the test conditions required for material characterization and the formulas and theories used in data calculation.In chapter 3,a nitrogen-defect co-doped carbonaceous material with uniform ultraporous structure was successfully synthesized by high temperature pyrolysis using zinc gluconate as intramolecular pore-forming agent.Porous nitrogen-doped electrocatalysts with uniform ultraporous structure and large specific surface area have been prepared at different temperatures.The synthesized electrocatalyst has two kinds of active sites（nitrogen and defect）,and the ultramicroporous structure promotes the triple mass transfer of reactants in the catalytic process,accelerates the breaking of oxygen bonds,and effectively inhibits the protonation of active sites in acidic electrolyte.The catalyst has good ORR catalytic activity,stability and methanol tolerance.In chapter 4,using furfural,nitrogen carbide（g-C₃N₄）and calcium chloride as precursors,two-dimensional porous graphene-like carbon nanosheets were synthesized by a two-template method as electrocatalysts.The two-dimensional porous graphene-like carbon nanosheets have large specific surface area（748 m²/g）,high pyridine nitrogen doping efficiency（13.6 wt%）and high graphitization degree.The material has high ORR activity,stability,methanol tolerance and good CO₂ adsorption capacity in both acid and alkaline conditions.