Synthesis And Electrochemical Performance Of Heteroatoms-doped Carbon Materials For Oxygen Reduction Reaction

The oxygen reduction reaction?ORR?is one of the key directions of fuel cell research,which mainly focus on the study of cathode catalysts.Metal-free catalysis behave excellent catalytic activity,especially heteroatom-doped carbon materials,which were considered the best substitute for Pt-based catalyst.Based on that,the heteroatom-doped carbon material were explored and analyzed from hree aspects:the kind of heteroatoms,the number of dopings and the kind of carbon materials.A series of doped carbon nanotubes?CNTs?were prepared by coating method with heteroatom-precursor,besides,doped activated carbon?C?and doped graphene?rGO?were systhsis by the same method.The electrochemical properties of the catalysts were investigated by means of a rotating disk device?RDE?,and their structures were characterized by TEM,XPS,Raman and BET.The results of electrochemical tests showed that the species,quantity,doping ratio and roasting temperature of heteroatoms all affected ORR activity.On the whole,the catalytic activity of the three-atom system is the best,the second atom is the second,the single atom is the worst.At the same time,boron elements show excellent research potential.?n=4.0?,ultimate diffusion current?J=5.1mA cm²?,half-wave potential(E_1/2=-0.20V),and so on.The prepared binary-doped NB-CNTs exhibited the best catalytic activity(n=4.1;E₀=-0.02V;E_1/2=-0.17V;J=5.3mA cm²);the prepared ternary doped NSB-CNTs(n=4.0;E₀=-0.05V;E_1/2=-0.18V;J=4.8 mA cm²)also exhibits extremely excellent catalytic activity.The experimental results showed that the carbon nanotubes had better ORR catalytic activity.