Preparation Of Co-N-G Catalyst And Study On Its Electrocatalytic Oxygen Reduction Reaction

Since the industrial revolution,energy has been the focus of scientific research.Fuel cell has the characteristics of high energy saving rate and low carbon emission,which can effectively solve the contradiction between energy demand growth and environmental protection.However,the development of fuel cell is restricted by the slow kinetics and high overpotential of oxygen reduction reaction(ORR).Although platinum(Pt)-based catalysts have excellent ORR electrocatalytic activity,their high cost and poor stability seriously hinder the popularization and application of fuel cells.Therefore,the focus of this field is to study efficient,stable and low-cost cathode ORR catalysts.In this paper,Co@Co-N-G and Co/Co O@Co-N-G catalysts were prepared through simple reflurization and pyrolysis by loading non-noble metal cobalt on nitrogen-doped graphene.Specific research contents mainly include the following two aspects:(1)Using graphene oxide(GO)as the carbon source and Schiff Base as the nitrogen source,the Co@Co-N-G ORR catalyst was successfully prepared by simple heat treatment.The electron transfer number of the catalyst was up to 3.68,showing excellent electrocatalytic activity.After 15000 s i-t test,the current retention rate is still 84%,showing good stability and methanol resistance.It may be that the effective synergistic effect of atomic and nanoscale metal species generated during pyrolysis is conducive to the improvement of catalyst activity and stability.(2)Cobalt-nitrogen doped mesoporous graphene catalyst Co/Co O@Co-N-G loaded with Co/Co O hollow nanoparticles was successfully prepared by using GO as a carbon source and adding N,N'-Bis(salicylidene)ethylenediamine cobalt salt in the process of reducing graphene oxide(GO)with hydrazine hydrate.The effective synergistic effect of Co/Co O hollow nanoparticles and cobalt-nitrogen doped mesoporous graphene makes it show excellent electrocatalytic activity.After 15000 s i-t test,the current retention rate was still 87%,and it also had good methanol resistance.