| With the continuous development of society,all kinds of non-renewable energy such as coal,petroleum and natural gas exhausting,therefore,finding and using sustainable green energy has become an important direction for future social development.Fuel cell is widely concerned because of its high conversion efficiency and low pollutant emission characteristics.However,due to the current use of commercial Pt/C as a cathode oxygen reduction electrocatalyst,which greatly increased its production costs,limiting its commercial applications.Therefore,the search for cheap,efficient non-precious metal catalysts for fuel cells oxygen reduction reaction(oxygen reduction reaction,ORR)become the most important development in the future.In this work,we synthesis an efficient and clean oxygen reduction reaction electrocatalyst by simple chemical synthesis and high temperature carbonization using cheap precursors.The main contents of this work are as follows:1.Synthesis of iron tetra-nitro phthalocyanine(FePC-NO2)and iron tetra-amino phthalocyanine(FePC-NH2)by solid-phase method and reduction method,respectively.The modified carbon black treated with nitric acid was used as a template,in the process of high temperature carbonization,FePC-NH2 polymerization on the surface of the modified carbon black to obtain a non－precious metal catalyst with Fe2O3 as active site.The initial potential and the half wave potential of oxygen reduction catalyst reached 0.98 V and 0.84 V at 0.1 M KOH,respectively,meanwhile,it also has great cycling stability and anti－methanol stability.2.In situ growth of ZIF-8 on the surface of SiO2,meanwhile,using ZIF-8@SiO2 as template and synthesizing polyaniline(PANI)on the surface of ZIF-8@SiO2.We obtain PANI@ZIF-8@SiO2-900 catalyst after high temperature carbonization in 900℃,and it has excellent ORR catalytic properties.We can see that PANI@ZIF-8@SiO2-900 catalyst shows the outstanding onset potential of 0.94 V and half-wave potential of 0.82 V,besides it has an efficiency nearly 4-electron transfer ORR pathway.3.In situ growth of ZIF-8 on the CNT surface and polymerization of polyaniline on the surface of ZIF-8@CNT,at the same time,the material was carbonized in 900℃ to get PANI@ZIF-8@ CNT-900 with Fe-Nxas an active site.The initial potential and the half wave potential of oxygen reduction catalyst reached 0.95 V and 0.82 V at 0.1 M KOH,respectively.Meanwhile,the catalyst also shows excellent circulation stability and antitoxic stability.In this paper,a suitable templating agent is added in the process of synthesizing cathodic oxygen reduction electrocatalysts,which effectively avoided the agglomeration of the active sites during the high temperature carbonization process,this provides a direction for us to prepare excellent oxygen reduction electrocatalysts in the future. |
