Preparation Of MOFs-graphene M-N_x-rGo Catalyst And Study On Its Oxygen Reduction Performance

Direct Methanol Fuel Cell(DMFC)has attracted worldwide attention as a clean,efficient and convenient technology which creates the possibility of portable mobile energy.However,the difficulties of cathode catalyst materials hinder the development of DMFC.This is because the cathode catalyst contains Pt,Pd and other precious metals,which is expensive but poor on resisting to methanol and electrochemical corrosion.Nowadays,M-N_x-C catalysts prepared by the heat treatment have attracted extensive attention because of their outstanding catalytic performance for oxygen reduction and excellent methanol resistance.In this paper,a series of M-N_x-C catalysts were prepared by introducing metal-organic framework(MOF)as the precursor with the M-N_x sites into a novel two-dimensional planar carbon material-----graphene.It undergoes a variety of physical characterization and oxygen reduction performance tests.The main research contents and conclusions are shown below:First,the Fe-N_x-rGO was prepared by Fe(NO3)3·9H2O,benzimidazole and reduced graphene oxide(rGO).The Fe-N_x catalytic sites of MOF may be doped into the graphene layer in order to improve the catalytic activity after being heated.This guess can be probably verified by XPS,FT-IR.Then,the Co-N_x-rGO was prepared by Co(NO3)2·6H2O,benzimidazole and reduced graphene oxide(rGO).Compared with the Fe-N_x-rGO prepared before,the oxygen reduction performance and the stability of the catalyst are greatly improved.In the end,we combined the performance of Fe-N_x-rGO and Co-N_x-rGO on oxygen reduction reaction,methanol resistance and electrochemical stability to prepare the binary catalyst.Compared with the Fe-N_x-rGO and Co-N_x-rGO,the electrocatalytic performance for oxygen reduction improved.The result of X-Ray Diffraction of it proved the combination of Co and Fe may promote the electrocatalytic performance for oxygen reduction.In this paper,a series of M-N_x-rGO oxygen reduction catalysts were prepared by solvothermal method using DMF as the solvent.The structure of the catalyst was studied,and the influences of several factors to the catalytic performance of M-N_x-rGO for Oxygen Reduction were discussed,which provides a reference for the further research of M-N_x-C and its wide application in commercial production.