Preparation And Properties Of Nitrogen-doped Ordered Porous Carbon Materials

Due to the low cost,superior catalytic properties and electrochemical stability,non-Pt catalysts are increasingly popular in fuel cell field.Highly ordered porous carbon material with long-range order of channels and high specific surface area,is one of the fuel cell catalyst material ideal candidate.In this paper,sublimable organic small molecule materials,such as metal phthalocyanines,metal porphyrins,etc.,mixing with nano inorganic oxide,with high temperature treatment,and then removing the inorganic oxide template,nitrogen-doped ordered porous Me-N-C catalysts with high specific surface area were prepared through nanocapillary-assisted condensation principle.We studied its catalytic oxygen reduction performance and electrochemical stability.In chapter 4,different nitrogen content samples were prepared by adjusting the mass ration of resol and OAPS which having unique octahedral cage structure.Cyclic voltammetry,galvanostatic charge-discharge tests were studied to characterize its capacitors performance.Conclusions are as follows:(1)Me-N-MC(Me=Fe,Co,Ni,Cu)catalysts have relatively uniform ordered mesoporous structure,indicating that the method for preparing such catalysts through nanocapillary-assisted condensation is universal.It can be applied to some small molecules which are difficult to dissolve,easy volatile and containing Fe,N elements.Ordered mesoporous materials with different catalyst structures can be synthesized by adjusting the inorganic oxide template.(2)Fe-N-MC-700 catalyst has the largest surface area,showing the most superior ORR performance and electrochemical stability with a high limiting current density of 5.6 mA cm~-22 and half-wave potential of-0.023 V vs.Ag/AgCl,Catalytic Kinetic analysis showed almost a four-electron transfer pathway.(3)SEM image shows that Fe-N-MC catalyst reversed replication monodisperse silica spheres structure,inverting copy quality was relatively high and its pore size conformed with the expected results,in which Fe-N-MC-40 exhibited the most superior ORR performance with half-wave potential of 0.04 V vs.Ag/AgCl.(4)OAPS with unique octahedral cage structure can form a uniform microporous structure after removing the Si-O bond.OAPS-95,OAPS-75,OAPS-50in three different porosity and nitrogen content samples were prepared by adjusting the mass ration of resol and OAPS.TEM,BET specific surface area and pore size distribution analysis showed a uniform pore structure about 1 nm of the samples.(5)OAPS-95 sample's specific capacitance has reached over 250 F/g with excellent capacitance retention of 61.4%while increasing the sweep rate from 0.5 A/g to 100 A/g.The symmetric cell of OAPS-95//OAPS-95 was further assembled to evaluate the practical application of synthesized materials.The quasi-rectangular shape of CV profiles and symmetric CDG curves confirmed its great electrochemical capacitive characteristic.The capacitance maintained about 95.4%of the initial value even after 10000 cycles,indicting the excellent stability of the micro-pores structure and nitrogen functional group.